Vol'eva, V. B.; Novikova, I. A.; Ivanova, E. V.; Ershov, V. V. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1986 , vol. 35, # 1 p. 199 - 202 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1986 , # 1 p. 215 - 218