NGUYEN, T. T. H., URBAN, J., KLINOTOVÁ, E., SEJBAL, J., PROTIVA, J., DRAŠAR, P., PROTIVA, M. Synthesis of Several Hydroxylated 23-(benzimidazol-2-YL-, benzoxazol-2-YL- and benzothiazol-2-YL) Norcholanes and Some Related Compounds. Collection of Czechoslovak Chemical Communications. 1995, 60(2), 257-275. ISSN 0010-0765.