Neunhoeffer, Hans; Clausen, Monika; Voetter, Hans-Dieter; Ohl, Harald; Krueger, Carl; Angermund, K.
Liebigs Annalen der Chemie, 1985 , # 9 p. 1732 - 1751

Ohsawa, Akio; Kaihoh, Terumitsu; Itoh, Takashi; Okada, Mamiko; Kawabata, Chikako; et al.
Chemical & Pharmaceutical Bulletin, 1988 , vol. 36, # 10 p. 3838 - 3848