Gornostaev, L. M.; Levdanskii, V. A.; Arnol'd, E. V.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1983 , p. 19 - 21
Khimiya Geterotsiklicheskikh Soedinenii, 1983 , vol. 19, # 1 p. 22 - 25