Krolevets, A. A.; Antipova, V. V.; Martynov, I. V. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1991 , vol. 40, # 7 p. 1410 - 1415 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1991 , # 7 p. 1593 - 1597