Rubina, K. I.; Iovel', I. G.; Gol'dberg, Yu. Sh.; Shimanskaya, M. V.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1990 , vol. 26, # 1 p. 43 - 46
Khimiya Geterotsiklicheskikh Soedinenii, 1990 , # 1 p. 50 - 53