Belezheva, V. S.; Mel'man, A. I.; Pol'shakov, V. I.; Anisimova, O. S.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1992 , vol. 28, # 2 p. 234 - 235
Khimiya Geterotsiklicheskikh Soedinenii, 1992 , # 2 p. 279 - 280