Pombrik, S. I.; Polunkin, E. V.; Peregudov, A. S.; Fedin, E. I.; Kravtsov, D. N. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1982 , vol. 31, # 6 p. 1148 - 1153 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1982 , # 6 p. 1289 - 1294