Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), , vol. 28, p. 1078 - 1080
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, , vol. 28, p. 1152 - 1155
Chemistry of Heterocyclic Compounds (New York, NY, United States), , vol. 3, p. 158 - 162
Khimiya Geterotsiklicheskikh Soedinenii, , vol. 3, p. 215 - 219