The Mount Kitanglad Range Natural Park in Bukidnon is an ASEAN Heritage Park that holds a special place in the history and heritage of World War II.

With a total land area of 47,270 hectares, it is located in northern Mindanao in the province of Bukidnon in Region 10. Mount Kitanglad is one of five peaks in the Kitanglad Mountain Range with an elevation of 2,899 meters above sea level. The Park was declared a Protected Area through Republic Act No. 8978 in 2000 and declared as ASEAN Heritage Park in 2009.

It’s the only location in the Philippines where the Cinchona Tree was raised and thrived purposely for Quinine production to treat Malaria.

Sept. 2, 1940.—High Commissioner Sayre and President Manuel L. Quezon inaugurate the new P1.1-million, 155-kilometer Cotabato-Bukidnon highway, still known today as the Sayre Highway. (Photo courtesy of Manuel L. Quezon III)

Then Philippine Commonwealth President Manuel L. Quezon issued Presidential Proclamation No. 89  establishing as Kaatoan Forest Reserve for Experimental Work in Quinine Tree Cultivation, Forest Protection, and Timber Protection a parcel of public land domain situated in the Municipality of Malaybalay, Bukidnon, Mindanao setting aside approximately 1,330 hectares (has.). solely for a Cinchona- Quinine Forest Reservation during the 1930s.

Presidential Proclamation No. 89 establishing as Kaatoan Forest Reserve for Experimental Work in Quinine Tree Cultivation, Forest Protection, and Timber Protection a parcel of public land domain situated in the Municipality of Malaybalay, Bukidnon, Mindanao

“During the time the area was proclaimed, it was a mere barrio of Malaybalay,” said Carlos P. Bagonoc of the CENRO Office of Department of Environment and Natural Resources (DENR) in Manolo Fortich, Bukidnon which provides technical guidance, through policies and programs for the effective protection, development, and conservation of forestlands and watersheds.

“Since the Cinchona Project was no longer a priority after the war, it has now become a part of the Regular Reforestation Project by the former Bureau of Forestry and later formed part of the Protected Area of Mt. Kitanglad Range Natural Park (MKRNP) under the National Integrated Protected Areas System (NIPAS Law  or Republic Act No. 7586, An Act Providing for the establishment and management of National Integrated Protected Areas System, Defining its scope and coverage, and for other purposes), and a growing tourist destination owing to its Cinchona trees, old growth forest/plantation of mixed and indigenous species, unique landscape, rich Cultural Communities  and home of the Philippine Eagle under the supervision of the Protected Area Superintendent, PENRO Office of Bukidnon based in Malaybalay,” Bagonoc noted.

“The Cinchona Forest Reserve is home to the Cinchona Plantation, established at Barangay Kaatoan in 1927, and is the only of its kind left in Asia and the Pacific where the medicinal plant Cinchona (Cinchona ledgeriana) and Four other Species is grown,” he added.

The Kaatoan plantation was an Experimental Research Station with a Cinchona Nursery and Plantation by forerunner of the  Ecosystems Research and Development Bureau (ERDB), the principal research and development (R & D) unit of the DENR.

This Bangkal look-alike is one of  the 4 species of Cinchona  at the Cinchona Forest Reserve at Kaatoan, Lantapan (photo by C.P. Bagonoc)

Cinchona, is a medium-sized tropical tree that can grow up 24 meters (79 ft) with a 60 centimeters (24 in) diameter, is a source of quinine that is used for malaria treatment.

The Experimental /Research Station covers an area of 1,725 hectares (4,260 acres) where 7 Cinchona tree species are found and is planted mostly with Albizza falcataria (= Falcataria moluccana), Benguet Pine with indigenous species other medicinal trees. Located 1,140 meters (3,740 ft) above sea level, the area is considered as the coldest place in Bukidnon with temperatures ranging from 13 to 18 °C (55 to 64 °F).

The Cinchona Story

Cinchona has been historically sought after for its medicinal value, as the bark of several species yields quinine and other alkaloids that were the only effective treatments against malaria  which made them of great economic and political importance up to the late 1940s although the curative properties of cinchona were known much earlier.

Quinine & World War II

The main problem facing soldiers in the fight against malaria in the early days of World War II was securing a safe and reliable supply of antimalarial drugs.  The traditional treatment for the disease was quinine due to its proven efficacy as an effective antimalarial, relatively few and mild side effects which made it the preferred anti-malarial medicine for various armed forces.

As World War II approached, the world supply of quinine was largely under control of the Netherlands.  The island of Java, a Dutch colony, was the world’s largest producer of cinchona, which thrived in its tropical climate. 

De Lairessestraat 142-144 (from right to left), Amsterdam where the Kinabureau was later located. (Vincent Steenburg)

A consortium of growers banded together to form the Kinabureau, based in Amsterdam, which dictated the supply of quinine and held an effective monopoly on this valuable commodity.  As a result, when the Nazis occupied the Netherlands in May 1940, they gained access to the warehouses and manufacturing capabilities of the Kinabureau, allowing them to dictate the distribution of processed quinine. 

With the Japanese occupation of Java and the Dutch East Indies in 1941, the raw supply of cinchona was cut, and the Allies found themselves without access to any supply of the gravely needed medication or its raw components.  A new source of antimalarials would be needed to fill the gap.

A 19th-century illustration of Cinchona calisaya
(Köhler–s_Medizinal-Pflanzen-179)

Cinchona trees remained the only economically practical source of quinine. However, with all sources of natural quinine in the hands of the Axis powers, the Allies were forced to turn to other antimalarials to aid their efforts against disease. 

Work on alternative drugs had been ongoing in the 1920s and 1930s, and some alternatives were already available when World War II broke out.  Although several efficient quinine total syntheses have been achieved, each of these alternatives had issues, mainly related to a variety of unpleasant side effects, and none could compete in economic terms with isolation of the alkaloid from natural sources.

Cinchona officinalis, the harvested bark (wikiwand.com)

Arthur F. Fischer

In his November 7, 1945 memorandum to President Sergio Osmeña on the Award of the Distinguished Service Star to Col. Arthur F. Fischer, Military Intelligence Service, United States Army, Col. Alejandro Melchor C.E., Philippine Army Military and Technical Adviser to the President, cited how Colonel Fischer, then Director of the Bureau of Forestry of the Philippines from 1917 to 1936, was solely responsible for the successful development of the cinchona plantation in Mindanao. Through his initiative and tireless energy, a government pilot plant for the extraction of totaquina from the cinchona bark was established in Manila.

A photo of Arthur F. Fischer  from the Dec. 15, 1933 issue of The Tribune (Manila) on the occasion of the Philippine Commonwealth Cabinet’s renewal of his contract as director of the Bureau of Forestry and acting director of the Bureau of Science. (trove.nla.gov.au)

“Thus, by providing the people with cheap and efficacious totaquina for the prevention and cure of malaria, Colonel Fischer has immeasurably aided the control of the tropical disease which was a great drawback in the development of the natural resources of the Philippines.”

In a 1935 Philippine Journal of Science article  on Philippine Totaquina authors Joaquin Marañon, Armando Perez and Paul E. Russel  Joaquin said Cinchona with an excellent alkaloidal content could be cultivated in the Philippines, and a satisfactory totaquina prepared locally and sold at a seventh of the present price of quinine.

The article related how the authors conducted clinical tests with totaquina extracted at the Bureau of Science from the bark of cinchona trees grown by the Bureau of Forestry in Bukidnon, Mindanao.

The Cinchona species originally came from South America’s Andes Mountain between Peru and Chile. It was raised by the Dutch in Java, Indonesia and later introduced by Fischer in the Philippines with seeds he got in Java from Consul General Hoover.

Success in Kaatoan

After a series of failed trials in Baguio (1912, 1916) and Impalutao, Impasug-ong, Bukidnon (1927), it was finally successfully raised in Kaatoan, Malaybalay, also in Bukidnon with nearly double the quinine content of the original.

The plantation was begun in 1927 and by 1935 already had 38, 000 trees of C. Ledgeriana, C. succirubra and C. hybrida, on an area of some 35 acres, situated at an altitude of 2, 500 feet, with an annual rainfall of 112 inches and a temperature ranging from 62° to 84°F.

May 1941 photos of the Kaatoan Research Laboratory and Experimental Cinchona Farm in Malaybalay, Bukidnon. (Philippines, Vol. 2 No.1, August 1942)

Some bark from 5-year old trees were analyzed with very satisfactory results. The percentage of alkaloids in the C. Ledgeriana bark was 9.6 per cent, as compared with 8.52 for India and 8.6 for Java. The yield for C. hybrida and C. succirubra was about 4.6 per cent, as compared with 6.25 and 7.7 per cent, for C. succirubra in India and Java, respectively.

The authors estimated that at least two million cases of malaria occurred yearly in the Philippines, and that 32, 400 kilograms of quinine were needed on the basis of 250 grains per case per year. The amount of quinine actually imported was often less than 2, 000 kilograms a year, because most Filipinos could not afford to buy it.

“Refined quinine is, in fact, an expensive luxury, a rich man’s remedy. Therefore, there is a very large field for the production of a still lower-priced product, such as totaquina. . . there is a potential market in the Philippines alone for more than 30, 000 kilograms a year.  It is required by malarious consumers who literally cannot afford to buy higher-priced drugs.”

Successful clinical trials were made by the authors at the Iwahig Penal Colony Hospital with totaquina prepared locally from Ledgeriana bark grown in the islands. 

In a 1939 paper  published in Asiatic Res.,35, 777, M. Ciuca states that in its search for an anti-malarial preparation cheaper than quinine but equally efficacious, the Malaria Commission of the League of Nations instituted research into the efficacy, compared with that of quinine, of a certain number of secondary alkaloid mixtures, such as kinetum, chineto, cinchona febrifuge, etc., used in the treatment of malaria in various countries.

Research carried out in more than 4,000 patients in malarious countries proved that the efficacy of preparations containing 60-80 per cent crystallizable alkaloids including 15 per cent quinine was equal to that of quinine alone.

The Commission named a preparation which was a mixture of cinchona bark alkaloids containing at least 75 per cent crystallizable alkaloids and not less than 15 per cent quinine as Totaquina. The advantage of the preparation was a distinctly lower price, mainly due to the method of extraction, even when its efficacy was equal to or only slightly less than that of quinine.

The Bureau of Forestry Cinchona Forest Reserve at Kaatoan, Malaybalay, (present day Lantapan) circa 1939. (NARA)

By the time World War II in the Pacific broke out in 1941, there were already 1,200,000 cinchona trees in Kaatoan, of which 750,000 survived the Japanese occupation.

Quinine for Bataan

The Distinguished Service Star citation for Col. Fisher details how he risked his life the only plane left as the Japanese closed in on Bataan to get quinine from the cinchona tree plantation he had developed in Bukidnon:

“In March 1942, fired with determination by the desperate plight of the malaria-stricken defenders of Bataan, he flew at great personal risk from Bataan to Mindanao where he organized a group composed mostly of his former old staff of foresters, for collecting the cinchona bark.”

The average soldier serving in the Pacific Theater of Operations (PTO) fighting against the Japanese faced a great many challenges and dangers.  Often overlooked by histories of the war, one of the most insidious of these was malaria. This disease, while not typically fatal to the infected soldier, would take him out of action for a prolonged period just as surely as if he had been wounded in battle.

American soldiers rush along a jungle trail on the Bataan Peninsula. (NARA)

According to the U.S. Army Heritage and Education Center, the Allied defenders of the Philippines were devastated by an epidemic of malaria.  About 24,000 of the 75,000 American and Filipino soldiers involved in the desperate campaign to stop the Japanese advance in 1942 were suffering from malaria. 

If these troops had been healthy, they could have greatly bolstered the defense against the 57,000 Japanese invaders early in the war. The lesson learned by the Army from the Philippines was that effective malaria control was essential for the successful conclusion of the campaign in the Pacific.

Allied soldiers taking quinine tablets (NARA)

By March 1942, close to 500 men with malaria were qualifying daily for admission to the hospital and by the end of the month  nearly 1,000 men per day were reporting to morning sick-call throughout the command with malaria so acute as to render them unfit for duty.

Efforts to supplement the nearly exhausted supply of quinine were made as often as possible by planes of the little Bamboo Fleet. On March 30 it was reported they had flown in close to 800,000 tablets- a mere fraction, however, of the estimated minimum of 3 million needed to quell the spread of the disease.

The Bamboo Fleet’s Bellanca Pacemaker “Old Number Nine”

One final attempt to help solve the quinine shortage began with a request for a volunteer from Bataan’s Bamboo Fleet to fly a special mission to Mindanao and back.

Based at the air base in Del Monte on the southernmost Philippine island of Mindanao, the Bamboo Fleet was operated by Captains Harold Slingsby, Dick Fellows, Joe Moore, Harvey Whitfield, and Bill Bradford. Captain Bill Bradford, a pre-war commercial air lines pilot in the islands, took it.

Of the group “Jitter Bill” Bradford was the most experienced pilot, having spent ten years as senior pilot and general manager for the Philippine Air Taxi Company (Patco) transporting people and cargo around the 7,000-plus islands in the Philippines.

“Jitter Bill came to be looked upon as the chief of the Bamboo Fleet,” Lt. Col. William E. Dyess later wrote in his book The Dyess Story. “He was a character I’ll long remember. His nickname came from no lack of nerve. No one in the squadron was braver. Day after day he flew the condemned and unarmed Bellanca, taking missions that sometimes appeared to  be hopeless. But he was jittery; there is no question about that. He probably was the only man in the air forces who would try to wind his eight-day panel clock six times an hour. His speech was jerky and rapid-fire. You’d walk toward him to say something, but before you’d get your mouth open he would pop out with: ‘You bet, boy! That’s right. That’s right.’ And Bill ended all conversations, no matter the topic, with: ‘Thank you, boy. Good luck, boy.’”

For this particular mission, Bradford would fly his Bellanca Pacemaker nicknamed “Old Number Nine,” a high-wing, cabin fuselage airplane capable of carrying seven passengers and notable for its long range (Pacemakers had set several long-distance records). It had a top speed of 180 miles per hour, and an average range of 900 miles.

However, like all of the rickety planes of the little Bamboo Fleet, the Bellanca was nearing the end of its operational life and had been condemned for private flying. There were only about 200 flying hours  left on its single engine, the battery was out, and it had no radio.

A still from a captured Japanese propaganda film shows what is believed to be the wrecked Bellanca “Old Number Nine,” on the side of the runway at Kindley Field, Corregidor. “Jitter Bill” Bradford flew the Bellanca as part of the Bamboo Fleet. (Japanese Government photo)

Just before dark on the night of March 31, he flew his Bellanca over Kindley Field on Corregidor where he picked up Lt. Col. Arthur Fischer. After clearing “Old Number Nine” from Kindley, he asked his passenger the reason for the trip.

Col. Fischer, it seems, had knowledge of an experimental cinchona plantation on the island of Mindanao. Cinchona, if extracted in time from the bark of the tree, could furnish enough quinine to save the command.

Unbeknownst to Bradford, the plantation, which was over 16,000 acres in size, had actually been started more than 15 years before by Fischer himself. Back in the early twenties he had smuggled cinchona seeds into Mindanao in order to break the Dutch monopoly on the drug.

The Dutch in the nearby East Indies had cornered the market on quinine, mainly because of their huge productive plantations in Java. Because of this  monopoly, they had been able to charge outrageous prices for the drug. Fischer’s plantation had helped make it available throughout the Philippines at a price most people could afford.

The Guerrilla Padre Fr. James Edward Haggerty, S.J.
(Photo from the Jesuit Archives courtesy of Media Wise Publications/MUSE Books through Mr. Ramoncito Ocampo Cruz)

After a brush with Japanese fighters on the way to Del Monte field, resulting in an abrupt ground-loop to finish the landing, the two men were met by Fischer’s old friend-Father Edward Haggerty-soon to be known as the legendary “Guerrilla Padre” for his work with the underground in Mindanao against the Japanese.

By noon, they had the Bellanca loaded with every available gallon of precious quinine that could be crammed into the plane’s empty cabin. Bradford, leaving Fischer behind to carry on with what he called “Operation Malaria,” made it back to Corregidor safely. Tragically, no more of the drug reached Bataan in time to be used.”

According to John Toland’s But Not in Shame,  Bradford would tally his 5,000th hour flying on a Bamboo Fleet mission ferrying out of Corregidor a cargo of live cinchona seeds.

Fischer escaped to Australia aboard one of the last undamaged B-17E Flying Fortress of the Royce Special Mission. This photo shows B-17E 41-2416 piloted by 1st Lt. Frank Bostrom, who earlier  flew Gen. MacArthur and his family from Del Monte Field to Australia on March 17, 1942. However, the B-17E “San Antonio Rose II” Serial Number 41-2447 piloted by Bostrom for the Royce Missions was spotted by a F1M2 Pete that released a 60kg bomb that hit the bomber and destroyed it on the ground on April 13, 1942 while parked at Del Monte Airfield after an early morning mission.  (U.S. Air Force photo)

Fischer shuttled back and forth in the old Bellanca plane until Bataan fell. Then he supplied American and Filipino guerrillas until he was ordered to Australia, on the last undamaged B-17 Flying Fortress of the Royce Special Mission.

During the Japanese occupation of World War II from 1942-1945,  the Bukidnon plantation was turned into a troops garrison and the bark/tissue of Cinchona tree were secretly harvested and smuggled by US operatives as Quinine source to treat Malaria to its affected troops deployed in Asia and the Pacific.

Col. Fischer secretly went to the area to lead the Cinchona bark gathering under the very noses of the Japanese garrison troops and brought it to an unspecified location near Macalajar Bay off Cagayan, Misamis where enough cinchona bark to manufacture 1,000,000 five-grain quinine tablets was transport by submarine to the Allied Headquarters in Australia under the leadership of General Douglas MacArthur.

For his heroics in helping save thousands of lives from malaria, Col. Arthur F. Fischer was awarded the Distinguished Service Star,  the third highest military award of the Armed Forces of the Philippines. It is awarded for eminently meritorious and valuable service rendered while holding a position of great responsibility.

“The skill, resourcefulness, loyalty and courage shown by this group of men who continued operation and maintenance of the plantation and distributed the cinchona bark throughout Mindanao and the Visayas under most difficult conditions during the Japanese occupation, thereby saving thousands of lives of guerillas and civilians, reflected outstandingly the inspiring leadership and unselfish devotion which Colonel Fischer has given to this highly important project.”

Fischer escaped from Bataan with cinchona seeds needed to develop a new supply of quinine for the Allies since all pre-war supplies had come from the Philippines now occupied by Imperial Japan.

The seedlings were planted in Guatemala, Costa Rica, Panama, and South America to produce anti-malaria doses of quinine for thousands of fighting men on Malaria-infested war fronts.

The year 1942 proved to be an absolute low point for the Army in its efforts to prevent malaria from ravaging troops deployed to the Pacific.  Infection rates were high across the entire South West Pacific Area (SWPA), and in some localized hotspots, astronomically so. 

One of the hardest hit areas was the Allied base at Milne Bay, Papua, which provided support for the campaign against Buna and Gona in late 1942 through January 1943.  During the campaign, malaria was rampant.  According to the U.S. Army Center of Military History, incidence of the disease reached an astounding 4,000 cases per 1,000 soldiers per annum.  Essentially, this was the equivalent of every single soldier at Milne Bay coming down with the disease at least four times throughout the course of the year.  This had a devastating effect on the efficiency of the units based there, where it was estimated that they lost around 12,000 man-days a month in work due to the disease.  Infection rates for the rest of the area of operations were not much better.

A medic at the 7th Portable Hospital in New Guinea stands by Cpl. Hugh Mereillo of the 163d Infantry, 41st Infantry Division, who is suffering from malaria, March 1943. While not usually fatal, malaria infected thousands of American and Allied troops in the Pacific Theater and took them out of action for prolonged periods of time. (NARA)

According to tabulations done after the war, Army medical personnel treated 47,663 cases of malaria in the SWPA in 1942.  The rate of infection was calculated at almost 251 cases per 1,000 troops in the entire area.  With a quarter of all troops infected, malaria was proving to be as large a menace to American operations as the Japanese.  

Additionally, it was discovered during the fighting at Buna that efforts to reduce the incidence of the disease quickly broke down once combat operations began.  The Medical Department estimated that casualties due to this disease for this period outnumbered combat casualties on an order of seven to ten times. 

Lieutenant General Robert L. Eichelberger, commander of the U.S. forces bogged down at Buna, noted that “disease was a surer and more deadly peril to us than enemy marksmanship.  We had to whip the Japanese before the malarial mosquito whipped us.”  The high rate of preventable losses of manpower and work-days seen in Papua were simply untenable if the United States and her allies were to take the initiative and defeat Japan’s armies in the Pacific.

The Battle of Buna proved costly for both the Allies and the Japanese.(NARA)

The fight against malaria was an ongoing struggle in the Pacific, and the disease affected both sides.  By the war’s end, the increasingly cut-off Japanese were suffering extreme rates of infection.  It was estimated that at times, up to ninety percent of Japanese troops in some locations were combat ineffective due to malaria and dysentery.  At Buna, where American forces had learned hard lessons about the impact the disease could have, the Japanese fared just as poorly.  After the battle, the 3d Portable Surgical Hospital records noted that every single Japanese prisoner they received was infected with malaria.

Both the Allies and Japanese suffered greatly from the malaria scourge during the war in the Pacific. (NARA)

For his war time services, Fischer was awarded the US Legion of Merit by the War Department for his work in directing the harvesting of cinchona seeds under battle conditions in Mindanao from March 26, 1942 to April 13, 1942, transporting the seeds to the United States, and collaborating in the work of organizing an American Cinchona Plantation for the production of quinine.

The delivery of medicine, particularly quinine, also made a critical difference between the life and death for many military personnel. Lt. Col. William Kennard of the Medical Corps, claimed that “through the initiative and sheer guts of the Air Corps pilots” the drugs they delivered enabled the treatment of several malaria cases and prevented morbidity.

Mitsubishi Ki-30 light bombers, (codenamed Ann) execute bombing runs against American and Filipinos at Bataan (warfaredefensehistorynetwork.com)

He also contended that treating malaria maintained the fighting force and delayed Bataan’s surrender by at least two weeks.  Those two weeks helped keep resistance alive in the Philippines for a total of six months, four months longer than the Japanese had planned.

Those extra months required the Japanese to invest additional manpower and resources in the Philippines as opposed to other areas of the Pacific theater, thus buying MacArthur more valuable time in preparing his forces to repel and eventually counterattack the enemy.

A colorized version  of U.S. Army Signal Corps officer Gaetano Faillace famous photo of Gen. Douglas MacArthur wading ashore during initial landings at Leyte, Philippines on 20 Oct 1944.

In novelist and historian William Edmond’s assessment of the overall effort in the initial months, he stated “Their accomplishment, little as it may have seemed in that enormous area of island-studded seas, was probably the deciding factor that kept the Japanese from trying to isolate Australia before we were able to prevent them.”

As President Franklin Roosevelt stated in his May 6, 1942 message to Wainwright shortly before the fall of  Corregidor and the surrender of the Philippines, “The American people ask no finer example of tenacity, resourcefulness, and steadfast courage.”

Mt. Kitanglad Range Natural Park (courtesy of Earl Ryan of Focalmatters Photography)

Today the Cinchona Forest Reserve at Kaatoan, Lantapan, Bukidnon adds prestige to the Mt. Kitanglad Range Natural Park’s stature as an ASEAN Heritage Park as the only of its kind left in Asia and the Pacific where the medicinal plant Cinchona is grown.

The 1.143 Km. Concrete Access Road Leading to the  Cinchona Forest Reserve, Brgy. Kaatoan, Lantapan, Bukidnon (DPWH-10)

Access to the area has recently been greatly improved with the completion of the 1,143-meter concrete access road in Lantapan, Bukidnon that leads to the Cinchona Forest Reserve in the Mt. Kitanglad Range Natural Park. The completion of this concrete road would hopefully promote greater awareness of the heritage and history of this area.

Few today remember the key role it played in delaying the surrender of the Philippines and upsetting Imperial Japan’s timetable for its planned conquest of Asia and the Pacific that would eventually lead to ultimate victory for the Allies.

In time, hopefully the coming generations could be made more aware of its story, and remember the valor and sacrifice of forgotten heroes like Fischer and Bradford, to pay them the proper respect and admiration they so richly deserve. (with additional research by Mike Baños)

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Sources/References:

1.       Tamesis, Florencio, Directory of Forestry, Manila. Self-Sufficiency in Quinine, Philippines Magazine Volume 2 No.1 (August 1942). Page 19

2.       Marañon, Joaquin ;  Perez, Amando ;  Russell, Paul F. Philippine TotaquinaJournal article, Philippine Journal of Science 1935 Vol.56 No.3 pp.229-255 pp. ref.2 folding figs., 22, ISSN : 0031-7683Record Number : 19362900415 (English)

3.       Melchor, A. (1945).  [Memorandum of Award of the Distinguished Service Star to Colonel Arthur Fischer]. Osmeña Collections, Rare Books Section. National Library of the Philippines, Manila, Philippines.

4.       Totaquina. Nature 145, 458 (1940). https://doi.org/10.1038/145458b0, Issue Date 23 March 1940, DOI https://doi.org/10.1038/145458b0

5.       Newspaper Article, trove.nla.gov.au

6.       The Shanghai Evening Post and Mercury, November 1, 1946, New York, N.Y.: Post-Mercury Post Co. Collection, Benchmark for Faithful Digital Reproductions of Monographs and Serials. Version 1. December 2002, Called New York ed., Jan. 1-Mar. 5, 1943; American ed., Mar. 12, 1943-1946, Columbia University Libraries; Americana, Volume 4 (1946) English

7.       Intelligence Activities in the Philippines during the Japanese Occupation, Documentary Appendices, Volume II, Intelligence Series (Unclassified), General Headquarters, United States Army Forces, Pacific, Military Intelligence Section, General Staff

8.       Howard, Richard A., The Role of Botanists during World War II in the Pacific Theatre, (Journal Article) Botanical Review, Vol. 60, No. 2 (Apr. – Jun., 1994), pp. 197-257 (61 pages) Published By: Springer, https://www.jstor.org/stable/4354228

9.       Cuvi ,Nicolás ,The Cinchona Program (1940-1945): science and imperialism in the exploitation of a medicinal plant, Facultad Latinoamericana de Ciencias Sociales, FLACSO-Ecuador; Centre d’Història de la Ciència, Universitat Autònoma de Barcelona. ncuvi@flacso.org.ec

10.   Seth, Paltzer. The Other Foe: The U.S. Army’s Fight against Malaria in the Pacific Theater, 1942-45armyhistory.org, retrieved 25 October 2020

11.   Young, Donald J., The Battle of Bataan: A Complete History, 2d Ed, page 173

12.    Zimmerman, Dwight Jon, The “Bamboo Fleet” Shuttle Service to Corregidor – February 16, 2012, defensemedianetwork.com

13.    Farrell, John F., The Bamboo Fleet: How a Ragtag Airlift Operation Supported Besieged U.S. Forces in the Philippines in World War II, Air Power History Summer 2012 Volume 59, Number 2 (www.afhistoricalfoundation.org)

14.    Kennard, Lt. Col. William J., Report on the Philippine and Australian Activities (Medical Corps, MD) pp. 10-11, Air Force Historical Research Agency, Maxwell AFB, Ala.

15.    Edmonds, Walter D., They Fought with What They Had: The Story of the Army Air Force in the Southwest Pacific, 1941-1942, (1951; Rept. Washington, D.C., Center for Air Force History, 1992), p. xvii

16.    Wainwright, Gen. Jonathan M., General Wainwright’s Story: The Account of Four Years of Humiliating Defeat, Surrender, and Captivity, ed. Robert Considine (1946, Rept. Westport,, Ct. Greenwood Press, 1970), p. 118