Marchenko, N. B.; Granik, V. G.; Persianova, I. V.; Glushkov, R. G.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1980 , vol. 16, # 6 p. 565 - 568
Khimiya Geterotsiklicheskikh Soedinenii, 1980 , # 6 p. 737 - 740