1. Lisa Ganora's Herbalchem http://www.herbalchem.net
2. Dr. James Duke's Phytochemical and Ethnobotanical Databases http://www.ars-grin.gov/duke/
3. American Society of Pharmacognosy Links http://www.phcog.org/links.html
4. Ethnomedicinals.com Pharmacognosy Links http://ethnomedicinals.com/pharmacognosy.htm
5. Antifungal activity of anthraquinone derivatives from Rheum emodi;Agarwal;J Ethnophar-macol,2000