Gol'dfarb, Ya. L.; Ostapenko, E'. G.; Ivanov, V.B.; Efremkin, A. F.; Litvinov, V. P.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1982 , vol. 18, # 11 p. 1148 - 1153
Khimiya Geterotsiklicheskikh Soedinenii, 1982 , vol. 18, # 11 p. 1482 - 1488

Gol'dfarb, Ya. L.; Ostapenko, E'. G.; Ivanov, V.B.; Efremkin, A. F.; Litvinov, V. P.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1982 , vol. 18, # 11 p. 1148 - 1153
Khimiya Geterotsiklicheskikh Soedinenii, 1982 , vol. 18, # 11 p. 1482 - 1488