Kovtunenko, V. A.; Dobrenko, T. T.; Voitenko, Z. V.; Tyltin, A. K.; Babichev, F. S. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1984 , vol. 20, # 9 p. 978 - 983 Khimiya Geterotsiklicheskikh Soedinenii, 1984 , vol. 20, # 9 p. 1200 - 1205