1. Dery BB, Ofsynia R, Ngatigwa C: Indigenous knowledge of medicinal trees and setting priorities for their domestication in Shinyanga region, Tanzania. Nairobi, Kenya: International Center for Research in Agroforestry; 1999.
2. Farnsworth NR: Ethnopharmacology and drug development. In Ethnobotany and the search for new drugs, Ciba Foundation Symposium 185. Chichester, Uk Prance GT: John Wiley and Sons; 1994:42-59.
3. Cotton CM: Ethnobotany: Principles and applications. Chichester, New York: John Wiley and Sons Ltd.; 1996.
4. WHO: Traditional medicine. Fact sheet No 134 2003.
5. Rai LK, Pankaj P, Sharma E: Conservation threats to some important medicinal plants of Sikkim Himalya. Biological Conservation 2000, 3: 27-34.