Remennikov, G. Ya.; Boldyrev, I. V.; Kapran, N. A.; Kurilenko, L. K. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1993 , vol. 29, # 3 p. 325 - 329 Khimiya Geterotsiklicheskikh Soedinenii, 1993 , # 3 p. 388 - 392