The Risk-Benefit Profile of Commonly Used Herbal Therapies: Ginkgo, St. John's Wort, Genseng, Echinacea, Saw Palmetto, and Kava
Ann Int Med 136:42-53, Ernst,E., 2002
Acute Dystonia Induced by Drug Treatment
BMJ 319:623-626, vanHarten,P.N.,et al, 1999