Drushlyak, A. G.; Ivashchenko, A. V.; Titov, V. V. Chemistry of Heterocyclic Compounds (New York, NY, United States)Khimiya Geterotsiklicheskikh Soedinenii, 19841984, vol. 2020, # 1010 p. 1155 - 11591399 - 1403 doi: 10.1007/BF00503611