Shvaika, O. P.; Lipnitskii, V. F.
J. Gen. Chem. USSR (Engl. Transl.), 1985 , vol. 55, # 11 p. 2608 - 2614,2318 - 2323

Lipnitskii, V. F.; Shvaika, O. P.
Chemistry of Heterocyclic Compounds (New York, NY, United States), 1988 , vol. 24, # 12 p. 1398 - 1403
Khimiya Geterotsiklicheskikh Soedinenii, 1988 , vol. 24, # 12 p. 1689 - 1695