Tokmakov, G. P.; Zemyanova. T. G.; Grandberg, I. I.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1984 , vol. 20, # 1 p. 47 - 51
Khimiya Geterotsiklicheskikh Soedinenii, 1984 , vol. 20, # 1 p. 56 - 60

Tokmakov, G.P.; Grandberg, I.I.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1980 , vol. 16, # 3 p. 244 - 247
Khimiya Geterotsiklicheskikh Soedinenii, 1980 , vol. 16, # 3 p. 331 - 334