Shorshnev, S. V.; Esipov, S. E.; Kuz'menko, V. V.; Gulevskaya, A. V.; Pozharskii, A. F.; et al. Chemistry of Heterocyclic Compounds (New York, NY, United States), 1990 , vol. 26, # 11 p. 1289 - 1301 Khimiya Geterotsiklicheskikh Soedinenii, 1990 , # 11 p. 1545 - 1558