The efficacy and safety of Tanacetum parthenium (feverfew) in migraine prophylaxis - a double-blind, multicentre, randomized placebo-controlled dose-response study. - Pfaffenrath,V.; Diener,H.C.; Fischer,M.; Friede,M.; Henneicke-von Zeppelin,H.H. (Cephalalgia, 2002)