1. Bisset NG, ed. Herbal Drugs and Phytopharmaceuticals. A Handbook for Practice on a Scientific Basis. (German Edition edited by Wichtl, M). Boca Raton, FL: CRC Press; 1994.
2. Wagner H, Bladt S. Plant Drug Analysis. 2nd Edition. Berlin: Springer-Verlag; 1996.
3. Sticher O. Quality of Gingko preparations. Planta Med. 1993(2):2–11.
4. DeFeudis FV. Gingko biloba Extract (EGb 761): Pharmacological Activities and Clinical Applications. Paris: Editions Scientifiques Elsevier; 1991.
5. Tyler VE. Herbs of Choice. The Therapeutic Use of Phytomedicinals. New York: Pharmaceutical Products Press; 1994.