Sidorenko, T. N.; Terent'eva, G. A.; Andrienko, O. S.; Savinykh, Yu. V.; Aksenov, V. S. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1983 , p. 156 - 160 Khimiya Geterotsiklicheskikh Soedinenii, 1983 , vol. 19, # 2 p. 192 - 196