Allakhverdiev, M. A.; Farzaliev, V. M.; Khoiskaya, T. M.; Ibragimov, N. Yu.; Cherkasova, E. M. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1984 , vol. 20, # 3 p. 261 - 263 Khimiya Geterotsiklicheskikh Soedinenii, 1984 , vol. 20, # 3 p. 327 - 329