Vol'eva, V. B.; Ivanov, E. V.; Batanov, I. A.; Ershov, V. V. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1986 , vol. 35, # 3 p. 648 - 650 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1986 , # 3 p. 706 - 709