Cytotoxic ent-Kaurane Diterpenoids from Isodon eriocalyx var. laxiflora - Niu, Xue-Mei; Li, Sheng-Hong; Li, Ma-Lin; Zhao, Qin-Shi; Mei, Shuang-Xi; Na, Zhi; Wang, Su-Jun; Lin, Zhong-Wen; Sun, Han-Dong (Planta Medica, 2002)