1. Demain AL, Zhang L (2005) Natural products and drug discovery. In: Zhang L, Demain AL (eds) Natural Products: Drug Discovery and Therapeutic Medicine. Humana,Totowa, NJ, p 3
2. Schippmann U, Leaman DJ, Cunnningham AB (2002) Biodiversity and the Ecosystem: Approaches in Agriculture, Forestry and Fisheries. 9th Regular Session of the Commission on Genetic Resources for Food and Agriculture. FAO, Rome, Italy 1
3. Anonymous (1994) Lancet 343:1513
4. Gupta R (1986) Integration of medicinal plants cultivation in forest and forest plantations of north-western Himalaya. In: Agroforestry Systems: A New Challenge. Indian Society of Tree Scientists, Solan, India, p 59
5. Van Wyk B-E, Wink M (2004) Medicinal Plants of the World. Briza, Pretoria, Briza