Prostakov, N. S.; Mikhalis Makuli; Mikhailova, N. M.; Sergeeva, N. D. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1984 , vol. 20, # 4 p. 413 - 416 Khimiya Geterotsiklicheskikh Soedinenii, 1984 , vol. 20, # 4 p. 510 - 513