Bulychev, Yu. N.; Korbukh, I. A.; Preobrazhenskaya, M. N.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1984 , vol. 20, # 2 p. 210 - 215
Khimiya Geterotsiklicheskikh Soedinenii, 1984 , vol. 20, # 2 p. 253 - 258