Zakharkin, L. I.; Guseva, V. V.; Churilova, I. M. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1983 , vol. 32, # 2 p. 419 - 421 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1983 , # 2 p. 461 - 463