Shanazarov, A. K.; Granik, V. G. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1987 , vol. 23, # 3 p. 359 - 360 Khimiya Geterotsiklicheskikh Soedinenii, 1987 , vol. 23, # 3 p. 423 - 424