Maslivets, A. N.; Mashevskaya, I. V.; Smirnova, L. I.; Andreichikov, Yu. S.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1991 , vol. 27, # 10 p. 1156
Khimiya Geterotsiklicheskikh Soedinenii, 1991 , vol. 27, # 10 p. 1431