Anikin, V. F.; Ganin, E. V.; Rozynov, B. V.; Zakharova, R. M.; Kamalov, G. L. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1982 , vol. 18, # 2 p. 193 - 196 Khimiya Geterotsiklicheskikh Soedinenii, 1982 , # 2 p. 246 - 249