Rozhkova, N. K.; Sabirov, K.; Seitanidi, K. L. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1983 , vol. 19, # 11 p. 1170 - 1173 Khimiya Geterotsiklicheskikh Soedinenii, 1983 , # 11 p. 1479 - 1482