Khilya,V.P. et al.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1977 , vol. 13, p. 948 - 953
Khimiya Geterotsiklicheskikh Soedinenii, 1977 , vol. 13, # 9 p. 1180 - 1185

Pivovarenko, V. G.; Khilya, V. P.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1991 , vol. 27, # 5 p. 496 - 501
Khimiya Geterotsiklicheskikh Soedinenii, 1991 , vol. 27, # 5 p. 625 - 631