Kukharev, B.F.; Stankevich, V.K.; Klimenko, G.R.; Terent'eva, V.P.; Kukhareva, V.A. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1986 , vol. 22, # 4 p. 440 - 442 Khimiya Geterotsiklicheskikh Soedinenii, 1986 , vol. 22, # 4 p. 536 - 538