Mochalov, S. S.; Fedotov, A. N.; Kupriyanova, E. A.; Shabarov, Yu. S.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1983 , vol. 19, # 5 p. 559 - 564
Khimiya Geterotsiklicheskikh Soedinenii, 1983 , vol. 19, # 5 p. 688 - 694