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
Anticholinergic Poisoning Associated with Herbal Tea
Arch Int Med 155:2245-2248, Hsu,C.K.,et al, 1995