Zhiryukhina, N. P.; Chukovskaya, E. Ts.; Makhaev, V. D.; Borisov, A. P. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1983 , vol. 32, # 3 p. 539 - 542 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1983 , # 3 p. 600 - 603