Zav'yalov, S. I.; Ezhova, G. I.; Budkova, T. K.; Dorofeeva, O. V.; Taganova, O. K. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1982 , vol. 31, # 2 p. 424 - 427 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1982 , # 2 p. 468 - 471