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

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

Victory, Pedro; Borrell, Jose I.; Cirujeda, Joan; Vidal-Ferran, Anton
Heterocycles, 1993 , vol. 36, # 4 p. 777 - 783