Przheval'skii, N. M.; Kostromina, L. Yu.; Grandberg, I. I.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1988 , vol. 24, p. 154 - 158
Khimiya Geterotsiklicheskikh Soedinenii, 1988 , vol. 24, # 2 p. 188 - 192