Sukhova, N. M.; Lapina, T. V.; Lidak, M. Yu. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1983 , vol. 19, # 11 p. 1207 - 1210 Khimiya Geterotsiklicheskikh Soedinenii, 1983 , # 11 p. 1521 - 1523