Antitumor-Promoting Activity of Coumarins from Citrus Plants - Ito, Chihiro; Itoigawa, Masataka; Ju-ichi, Motoharu; Sakamoto, Naoyuki; Tokuda, Harukuni; Nishino, Hoyoku; Furukawa, Hiroshi (Planta Medica, 2005)