Krauze, A.A.; Pelcher, Yu.E'.; Kalme, Z.A.; Dubar, G.Ya. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1984 , vol. 20, # 8 p. 935 Khimiya Geterotsiklicheskikh Soedinenii, 1984 , # 8 p. 1140 - 1141