| Erythroxylum coca|
Coca, Erythroxylum coca, is a plant in the family Erythroxylaceae, native to western South America. The plant plays a significant role in traditional Andean culture. Coca is best known throughout the world because of its alkaloids, which include cocaine, a powerful stimulant.
The Erythroxylum coca plant resembles a blackthorn bush, and grows to a height of 2–3 m (7–10 ft). The branches are straight, and the leaves, which have a green tint, are thin, opaque, oval, and taper at the extremities. A marked characteristic of the leaf is an areolated portion bounded by two longitudinal curved lines, one line on each side of the midrib, and more conspicuous on the under face of the leaf.
The flowers are small, and disposed in little clusters on short stalks; the corolla is composed of five yellowish-white petals, the anthers are heart-shaped, and the pistil consists of three carpels united to form a three-chambered ovary. The flowers mature into red berries.
Species and classification
There are twelve main species and varieties. Two subspecies, Erythroxylum coca var. coca and Erythroxylum coca var. ipadu, are almost indistinguishable phenotypically; a related high cocaine-bearing species has two subspecies, Erythroxylum novogranatense var. novogranatense and Erythroxylum novogranatense var. truxillense that are phenotypically similar, but morphologically distinguishable. Under the older Cronquist system of classifying flowering plants, this was placed in an order Linales; more modern systems place it in the order Malpighiales.
Coca is traditionally cultivated in the lower altitudes of the eastern slopes of the Andes (the Yungas), or the highlands depending on the species grown. Since ancient times, its leaves have been an important trade commodity between the lowlands where it is grown and the higher altitudes where it is widely consumed by the Andean peoples of Peru, Colombia, Ecuador, Venezuela, Bolivia and northwestern Argentina.
Fresh samples of the dried leaves are uncurled, are of a deep green on the upper, and a grey-green on the lower surface, and have a strong tea-like odor. When chewed, they produce a pleasurable numbness in the mouth, and have a pleasant, pungent taste. They are traditionally chewed with lime to increase the release of the active ingredients from the leaf. Older species have a camphoraceous smell and a brownish color, and lack the pungent taste.
The seeds are sown from December to January in small plots (almacigas) sheltered from the sun, and the young plants when at 40–60 cm in height are placed in final planting holes (aspi), or if the ground is level, in furrows (uachos) in carefully weeded soil. The plants thrive best in hot, damp and humid locations, such as the clearings of forests; but the leaves most preferred are obtained in drier areas, on the hillsides. The leaves are gathered from plants varying in age from one and a half to upwards of forty years, but only the new fresh growth is harvested. They are considered ready for plucking when they break on being bent. The first and most abundant harvest is in March after the rainy season, the second is at the end of June, and the third in October or November. The green leaves (matu) are spread in thin layers on coarse woollen cloths and dried in the sun; they are then packed in sacks, which must be kept dry in order to preserve the quality of the leaves.
|Morphology of the coca plant|
The pharmacologically active ingredient of coca is the alkaloid cocaine, which is found in the amount of about 0.3 to 1.5%, averaging 0.8%, in fresh leaves. Besides cocaine, the coca leaf contains a number of other alkaloids, including methylecgonine cinnamate, benzoylecgonine, truxilline, hydroxytropacocaine, tropacocaine, ecgonine, cuscohygrine, dihydrocuscohygrine, nicotine and hygrine. When chewed, coca acts as a mild stimulant and suppresses hunger, thirst, pain, and fatigue.
Absorption of cocaine from the leaf is much less rapid and efficient than from the purified forms of cocaine, and it does not cause the euphoric and psychoactive effects associated with use of the drug. Some proponents have claimed that cocaine itself is not an active ingredient when unprocessed coca leaf is chewed or brewed as an infusion. However, studies have shown that small but measurable amounts of cocaine are present in the bloodstream after consumption of coca tea. Addiction or other deleterious effects from the consumption of the leaf in its natural form have not been documented.
Traces of coca have been found in mummies dating 3000 years back. Other evidence dates the communal chewing of coca with lime 8000 years back. Extensive archaeological evidence for the chewing of coca leaves dates back at least to the sixth century A.D. Moche period, and the subsequent Inca period, based on mummies found with a supply of coca leaves, pottery depicting the characteristic cheek bulge of a coca chewer, spatulas for extracting alkali and figured bags for coca leaves and lime made from precious metals, and gold representations of coca in special gardens of the Inca in Cuzco
Coca chewing may originally have been limited to the eastern Andes before its introduction to the Incas. As the plant was viewed as having a divine origin, its cultivation became subject to a state monopoly and its use restricted to nobles and a few favored classes (court orators, couriers, favored public workers, and the army) by the rule of the Topa Inca (1471–1493). As the Incan empire declined, the leaf became more widely available. After some deliberation, Philip II of Spain issued a decree recognizing the drug as essential to the well-being of the Andean Indians but urging missionaries to end its religious use. The Spanish are believed to have effectively encouraged use of coca by an increasing majority of the population to increase their labor output and tolerance for starvation, but it is not clear that this was planned deliberately.
Coca was first introduced to Europe in the 16th century, but did not become popular until the mid-19th century, with the publication of an influential paper by Dr. Paolo Mantegazza praising its stimulating effects on cognition. This led to invention of cocawine and the first production of pure cocaine. Cocawine (of which Vin Mariani was the best-known brand) and other coca-containing preparations were widely sold as patent medicines and tonics, with claims of a wide variety of health benefits. The original version of Coca-cola was among these. These products became illegal in most countries outside of South America in the early 20th century, after the addictive nature of cocaine was widely recognized. In 1859, Albert Niemann of the University of Göttingen became the first person to isolate the chief alkaloid of coca, which he named "cocaine".
In the early twentieth century the Dutch colony of Java became a leading exporter of coca leaf. By 1912 shipments to Amsterdam, where the leaves were processed into cocaine, reached 1 million kg, overtaking the Peruvian export market. Apart from the years of the First World War, Java remained a greater exporter of coca than Peru until the end of the 1920s. Other colonial powers also tried to grow coca (including the British in India), but with the exception of the Japanese in Formosa, these were relatively unsuccessful.
In recent times (2006), the governments of several South American countries, such as Peru, Bolivia and Venezuela, have defended and championed the traditional use of coca, as well as the modern uses of the leaf and its extracts in household products such as teas and toothpaste and condoms. (see Industrial Use below)
Traditional medical uses of coca are foremost as a stimulant to overcome fatigue, hunger, and thirst. It is considered particularly effective against altitude sickness. It also is used as an anesthetic to alleviate the pain of headache, rheumatism, wounds and sores, etc. Before stronger anaesthetics were available, it also was used for broken bones, childbirth, and during trephining operations on the skull. Because cocaine constricts blood vessels, the action of coca also serves to oppose bleeding, and coca seeds were used for nosebleeds. Indigenous use of coca has also been reported as a treatment for malaria, ulcers, asthma, to improve digestion, to guard against bowel laxity, as an aphrodisiac, and credited with improving longevity. Modern studies have supported a number of these medical applications.[which?]
Coca has also been a vital part of the religious cosmology of the Andean peoples of Peru, Bolivia, Ecuador, Colombia and northern Argentina and Chile from the pre-Inca period through the present. They follow the making and worship the coca beans when they are ready. Coca leaves play a crucial part in offerings to the apus (mountains), Inti (the sun), or Pachamama (the earth). Coca leaves are also often read in a form of divination analogous to reading tea leaves in other cultures. As one example of the many traditional beliefs about coca, it is believed by the miners of Cerro de Pasco to soften the veins of ore, if masticated (chewed) and thrown upon them (see also Cocomama).
Traditionally, coca leaves are prepared either as a chew or as a tea (mate de coca).
The activity of chewing coca is called mambear, chacchar or acullicar, borrowed from Quechua, coquear (northern Argentina), or in Bolivia, picchar, derived from the Aymara language. The Spanish masticar is also frequently used, along with the slang term "bolear," derived from the word "bola" or ball of coca pouched in the cheek while chewing. Typical coca consumption is about two ounces per day, and contemporary methods are believed to be unchanged from ancient times. Coca is kept in a woven pouch (chuspa or huallqui). A few leaves are chosen to form a quid (acullico) held between the mouth and gums. Doing so usually causes users to feel a tingling and numbing sensation in their mouths. (The common dental anaesthetic Novocaine has a similar effect.) Chewing coca leaves is most common in indigenous communities across the central Andean region, particularly in places like the highlands of Colombia, Ecuador, Bolivia and Peru, where the cultivation and consumption of coca is as much a part of the national culture similar to chicha, like wine is to France or beer is to Germany. It also serves as a powerful symbol of indigenous cultural and religious identity, amongst a diversity of indigenous nations throughout South America. Bulk bags of coca leaves are sold in local markets and by street vendors.
Coca is still chewed in the traditional way, with a tiny quantity of ilucta (a preparation of the ashes of the quinoa plant) added to the coca leaves; it softens their astringent flavor and activates the alkaloids. Other names for this basifying substance are llipta in Peru and the Spanish word lejía, lye in English. The consumer carefully uses a wooden stick (formerly often a spatula of precious metal) to transfer an alkaline component into the quid without touching his flesh with the corrosive substance. The alkali component, usually kept in a gourd (ishcupuro or poporo), can be made by burning limestone to form unslaked quicklime, burning quinoa stalks, or the bark from certain trees, and may be called ilipta, tocra or mambe depending on its composition. Many of these materials are salty in flavor, but there are variations. The most common base in the La Paz area of Bolivia is a product known as lejía dulce (sweet lye), which is made from quinoa ashes mixed with aniseed and cane sugar, forming a soft black putty with a sweet and pleasing flavor. In some places, baking soda is used under the name bico.
In the Sierra Nevada de Santa Marta, on the Caribbean Coast of Colombia, coca is consumed by the Kogi, Arhuaco and Wiwa by using a special device called poporo. The poporo is the mark of manhood. It represents the womb and the stick is a phallic symbol. The movements of the stick in the poporo symbolize the sexual act. For a man the poporo is a good companion that means "food", "woman", "memory" and "meditation". It is important to stress that poporo is the symbol of manhood. But it is the woman who gives men their manhood. When the boy is ready to be married, his mother will initiate him in the use of the coca. This act of initiation is carefully supervised by the mama, a traditional priest-teacher-leader.
Although coca leaf chewing is common only among the indigenous populations, the consumption of coca tea (Mate de coca) is common among all sectors of society in the Andean countries, and is widely held to be beneficial to health, particularly in the high altitudes. Coca leaf is sold packaged into teabags in most grocery stores in the region, and establishments that cater to tourists generally feature coca tea.
Commercial and industrial uses
In the Andes commercially manufactured coca teas, granola bars, cookies, hard candies, etc. are available in most stores and supermarkets, including upscale suburban supermarkets.
Coca tea is produced industrially from coca leaves in South America by a number of companies, including Enaco S.A. (National Company of the Coca) a government enterprise in Peru. Coca leaves are also found in a brand of herbal liqueur called "Agwa de Bolivia" (grown in Bolivia and de-cocainized in Amsterdam), and a natural flavouring ingredient in Red Bull Cola, that was launched in March 2008.
Beginning in the early 21st century, there has been a movement in Bolivia, Peru, and Venezuela to promote and expand legal markets for the crop. The presidents of these three countries have personally identified with this movement. In particular, Evo Morales of Bolivia (elected in December 2005) was a coca growers union leader. Morales asserts that "la coca no es cocaína"—the coca leaf is not cocaine. During his speech to the General Assembly of the United Nations on September 19, 2006, he held a coca leaf in his hand to demonstrate its innocuity.
Alan García, president of Peru, has recommended its use in salads and other edible preparations. A Peruvian-based company has announced plans to market a modern version of Vin Mariani, which will be available in both natural and de-cocainized varieties.
In Venezuela, president Hugo Chávez said in a speech on January 2008 that he chews coca every day, and that his "hook up" is Bolivian president Evo Morales. Chávez reportedly said "I chew coca every day in the morning... and look how I am" before showing his biceps to his audience, the Venezuelan National Assembly.
On the other hand, the Colombian government has recently moved in the opposite direction. For years, Bogotá has allowed indigenous coca farmers to sell coca products, promoting the enterprise as one of the few successful commercial opportunities available to recognized tribes like the Nasa, who have grown it for years and regard it as sacred. In December 2005, the Paeces, a Tierradentro (Cauca) indigenous community, started in December to produce a carbonated soft drink called "Coca Sek". The production method belongs to the resguardos of Calderas (Inzá) and takes about 150 kg of coca per 3,000 produced bottles. The drink was never sold widely in Colombia, the efforts to do so ended in May 2007 when it was abruptly banned by the Colombian government.
Coca Colla is an energy drink which is produced in Boliva with the use of coca extract as its base. It was launched on the Bolivian market in La Paz, Santa Cruz and Cochabamba in mid-April 2010.
Probably the earliest reference to coca in English literature is Abraham Cowley's poem "The Legend of Coca" in his 1662 collection of poems "Six Books of Plants".
One of the best known examples of coca's reference in fiction is Patrick O'Brian's character, Stephen Maturin. In many of the more than twenty book series, a.k.a. Aubrey-Maturin series, Maturin expounds the benefits of coca. However, the reader is made aware of the truly addictive effects of the drug when rats, who have found the coca (Erythroxylum coca), become seriously addicted and scour the ship looking for it.
Coca leaf is the raw material for the manufacture of the drug cocaine, a powerful stimulant and anaesthetic extracted chemically from large quantities of coca leaves. Today, since it has mostly been replaced as a medical anaesthetic by synthetic analogues such as procaine, cocaine is best known as an illegal recreational drug. The cultivation, sale, and possession of unprocessed coca leaf (but not of any processed form of cocaine) is generally legal in the countries – such as Bolivia, Peru, Chile and Argentina – where traditional use is established, although cultivation is often restricted in an attempt to prevent the production of cocaine.
The prohibition of the use of the coca leaf except for medical or scientific purposes was established by the United Nations in the 1961 Single Convention on Narcotic Drugs. The coca leaf is listed on Schedule I of the 1961 Single Convention together with cocaine and heroin. The Convention determined that “The Parties shall so far as possible enforce the uprooting of all coca bushes which grow wild. They shall destroy the coca bushes if illegally cultivated” (Article 26), and that, “Coca leaf chewing must be abolished within twenty-five years from the coming into force of this Convention” (Article 49, 2.e).
The rationale for including the coca leaf in the 1961 Single Convention is mainly rooted in a report requested of the United Nations by the permanent representative of Peru that was prepared by a commission that visited Bolivia and Peru briefly in 1949 to “investigate the effects of chewing the coca leaf and the possibilities of limiting its production and controlling its distribution.” The Commission of Enquiry on the Coca Leaf study, published in 1950, concluded that the effects of chewing coca leaves were negative, even though chewing coca was defined as a habit, not an addiction.
The report was sharply criticised for its arbitrariness, lack of precision and racist connotations. The team members’ professional qualifications and parallel interests were also criticised, as were the methodology used and the incomplete selection and use of existing scientific literature on the coca leaf. Questions have been raised as to whether a similar study today would pass the scrutiny and critical review to which scientific studies are routinely subjected.
Despite the legal restriction, coca chewing and drinking of coca tea is carried out daily by millions of people in the Andes as well as considered sacred within indigenous cultures. They claim that most of the information provided about the traditional use of the coca leaf and its modern adaptations are erroneous. This has made it impossible to shed light on the plant’s positive aspects and its potential benefits for the physical, mental and social health of the people who consume and cultivate it.
In an attempt to obtain legal recognition for the traditional use of coca, Peru and Bolivia negotiated paragraph 2 of Article 14 into the 1988 United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, stipulating that measures to eradicate illicit cultivation and to eliminate illicit demand “should take due account of traditional licit use, where there is historic evidence of such use.” Bolivia also made a formal reservation to the 1988 Convention, which required countries to adopt measures to establish the use, consumption, possession, purchase or cultivation of the coca leaf for personal consumption as a criminal offence. Bolivia stated that “the coca leaf is not, in and of itself, a narcotic drug or psychotropic substance” and stressed that its “legal system recognizes the ancestral nature of the licit use of the coca leaf, which, for much of Bolivia’s population, dates back over centuries.”
However, the International Narcotics Control Board (INCB) – the independent and quasi-judicial control organ for the implementation of the United Nations drug conventions – denied the validity of article 14 in the 1988 Convention over the requirements of the 1961 Convention, or any reservation made by parties, since it does not "absolve a party of its rights and obligations under the other international drug control treaties."
In recent years the current legal status of the coca leaf is more and more questioned. Even the INCB stated in its 1994 Annual Report that "mate de coca, which is considered harmless and legal in several countries in South America, is an illegal activity under the provisions of both the 1961 Convention and the 1988 Convention, though that was not the intention of the plenipotentiary conferences that adopted those conventions." It implicitly also dismissed the original report of the Commission of Enquiry on the Coca Leaf by recognizing that "there is a need to undertake a scientific review to assess the coca-chewing habit and the drinking of coca tea."
Nevertheless, the INCB on other occasions did not show signs of an increased sensitivity towards the Bolivian claim on the rights of their indigenous population, and the general public, to consume the coca leaf in a traditional manner by chewing the leaf, and even goes as far as to consider drinking coca tea, as "not in line with the provisions of the 1961 Convention." The Board considered Bolivia, Peru and a few other countries that allow such practises to be in breach with their treaty obligations, and insisted that “each party to the Convention should establish as a criminal offence, when committed intentionally, the possession and purchase of coca leaf for personal consumption.”
In reaction to the 2007 Annual Report of the INCB, the Bolivian government announced that it would formally issue a request to the United Nations to unschedule the coca leaf of List 1 of the 1961 UN Single Convention.
Legal status by country
Outside of South America, most countries' laws make no distinction between the coca leaf and any other substance containing cocaine, so the possession of coca leaf (except for de-cocainized leaf) is prohibited.
In the Netherlands, coca leaf is legally in the same category as cocaine, both are List I drugs of the Opium Law. The Opium Law specifically mentions the leafs of the plants of the genus Erythroxylon. However, the possession of living plants of the genus Erythroxylon are not actively prosecuted, even though they are legally forbidden.
In the United States, a Stepan Company plant in Maywood, New Jersey has the only license to legally import coca leaf. The company manufactures pure cocaine for medical use and also produces a cocaine-free extract of the coca leaf, which is used as a flavoring ingredient in Coca-Cola. According to the Bolivian press, Coca-Cola legally imported 204 tons of coca leaf in 1996.
Since the 1980s, the countries in which coca is grown have come under political and economic pressure from the United States to restrict the cultivation of the crop, in order to reduce the supply of cocaine on the international market.
Article 26 of the Single Convention on Narcotic Drugs requires nations that allow the cultivation of coca to designate an agency to regulate said cultivation and take physical possession of the crops as soon as possible after harvest, and to destroy all coca which grows wild or is illegally cultivated. The effort to enforce these provisions, referred to as coca eradication, has involved many strategies, ranging from aerial spraying of herbicides on coca crops to assistance and incentives to encourage farmers to grow alternate crops.
This effort has been politically controversial, with proponents claiming that the production of cocaine is several times the amount needed to satisfy legal demand, and inferring that the vast majority of the coca crop is destined for the illegal market, which not only contributes to the major social problem of drug abuse, but also financially supports insurgent groups that collaborate with drug traffickers in some cocaine-producing territories. Critics of the effort claim that it creates hardship primarily for the coca growers, many of whom are poor and have no viable alternative way to make a living, causes environmental problems, that it is not effective in reducing the supply of cocaine, in part because cultivation can move to other areas, and that any social harm created by drug abuse is only made worse by the war on drugs.
More recently, coca has been reintroduced to the United States as a flavoring agent in the herbal liqueur Agwa.
- ↑ Illicit Production of Cocaine - [www.rhodium.ws]
- ↑ Jenkins AJ, Llosa T, Montoya I, Cone EJ., "Identification and quantitation of alkaloids in coca tea," Forensic Sci Int. 9 February 1996;77(3):179-89.
- ↑ 3.0 3.1 Weil AT., "The therapeutic value of coca in contemporary medicine," J Ethnopharmacol. 1981 Mar-May;3(2-3):367-76.
- ↑ Hanna JM, Hornick CA., "Use of coca leaf in southern Peru: adaptation or addiction," Bull Narc. 1977 Jan-Mar;29(1):63-74.
- ↑ Rivera MA, Aufderheide AC, Cartmell LW, Torres CM, Langsjoen O., "Antiquity of coca-leaf chewing in the south central Andes: a 3,000 year archaeological record of coca-leaf chewing from northern Chile," J. Psychoactive Drugs. 2005 Dec;37(4):455-8.
- ↑ Dillehay et al (2010). "Early Holocene coca chewing in northern Peru". Antiquity 84 (326): 939–953. http://antiquity.ac.uk/ant/084/ant0840939.htm.
- ↑ 7.0 7.1 Robert C. Peterson, Ph.D. (1977-05). "NIDA research monograph #13: Cocaine 1977, Chapter I". http://www.nida.nih.gov/pdf/monographs/13.pdf. Retrieved 2007-05-26.
- ↑ 8.0 8.1 Eleanor Carroll, M.A.. "Coca: the plant and its use". http://sad.health.org/pub/AD03991.pdf. Retrieved 2007-05-26.
- ↑ Inciardi, James A. (1992). The War on Drugs II. Mayfield Publishing Company. p. 6. ISBN 1-55934-016-9.
- ↑ 10.0 10.1 Musto, D.F. (1998), "International traffic in coca through the early 20th century", Drug and Alcohol Dependence 49 (2), pp. 145-156
- ↑ May, Clifford D. "How Coca-Cola Obtains Its Coca", The New York Times, July 1, 1998. "A Stepan laboratory in Maywood, N.J., is the nation's only legal commercial importer of coca leaves, which it obtains mainly from Peru and, to a lesser extent, Bolivia. Besides producing the coca flavoring agent for Coca-Cola, Stepan extracts cocaine from the coca leaves, which it sells to Mallinckrodt Inc., a St. Louis pharmaceutical manufacturer that is the only company in the United States licensed to purify the product for medicinal use."
- ↑ Benson, Drew. "Coca kick in drinks spurs export fears", The Washington Times, April 20, 2004. "Coke dropped cocaine from its recipe around 1900, but the secret formula still calls for a cocaine-free coca extract produced at a Stepan Co. factory in Maywood, N.J. Stepan buys about 100 metric tons of dried Peruvian coca leaves each year, said Marco Castillo, spokesman for Peru's state-owned National Coca Co."
- ↑ 13.0 13.1 13.2 Coca Yes, Cocaine No? Legal Options for the Coca Leaf, Transnational Institute, Drugs & Conflict Debate Paper 13, May 2006
- ↑ (Spanish) Empresa Nacional de la Coca S.A
- ↑ Peruvian Drug Control Agency: Coca Cola Buys Coca Leaves, The Narco News Bulletin, January 28, 2005
- ↑ Agwabuzz.com Agwa de Bolivia herbal liqueur official site
- ↑ The Cola from Red Bull[dead link]
- ↑ Statement of Evo Morales Aima, President of Bolivia at the 61st session of the United Nations General Assembly, September 19, 2006
- ↑ Bolivia and Peru Defend Coca Use March 6, 2008. "The United Nations lacks respect for the indigenous people of Peru and Bolivia who have used the coca leaf since forever," said Peruvian Congresswoman Maria Sumire. "For indigenous people, coca is a sacred leaf that is part of their cultural identity," she said.
- ↑ "Evo Morales launches 'Coca Colla'". Telegraph. 10 January 2010. http://www.telegraph.co.uk/news/worldnews/southamerica/bolivia/6962746/Evo-Morales-launches-Coca-Colla.html. Retrieved 22 January 2010.
- ↑ "Bolivia banks on 'Coca Colla,' fizzy coca-leaf drink". AFP. 10 January 2010. http://www.google.com/hostednews/afp/article/ALeqM5jFUaMjoArM16Nqy4rY--1-Z2lPpg. Retrieved 22 January 2010.
- ↑ Single Convention on Narcotic Drugs
- ↑ Commission of Enquiry on the Coca Leaf, UNGASS 10-year review website, Transnational Institute
- ↑ The Commission of Enquiry on the Coca Leaf, Bulletin on Narcotics - 1949 Issue 1
- ↑ 25.0 25.1 The resolution of ambiguities regarding coca, Transnational Institute, March 2008
- ↑ Status of treaty adherence, United Nations Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances
- ↑ Report of the International Narcotics Control Board for 2007, paragraph 220
- ↑ Evaluation of the effectiveness of the international drug control treaties, Supplement to the INCB Annual Report for 1994 (Part 3)
- ↑ Evaluation of the effectiveness of the international drug control treaties, Supplement to the INCB Annual Report for 1994 (Part 1)
- ↑ Report of the International Narcotics Control Board for 2007, paragraph 217
- ↑ Response to the 2007 Annual Report of the International Narcotics Control Board, International Drug Policy Consortium (IDPC), March 2008
- ↑ Report of the International Narcotics Control Board for 2007, paragraph 219
- ↑ Statement of Hugo Fernandez, vice-minister of Foreign Affairs of Bolivia, at the 51st period of the Commission on Narcotic Drugs, Vienna, March 10, 2008
- Turner C. E., Elsohly M. A., Hanuš L., Elsohly H. N. Isolation of dihydrocuscohygrine from Peruvian coca leaves. Phytochemistry 20 (6), 1403-1405 (1981)
- "History of Coca. The Divine Plant of the Incas" by W. Golden Mortimer, M.D. 576 pp. And/Or Press San Francisco, 1974. This title has no ISBN.
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