Ryashentseva, M. A.; Belanova, E. P.; Minachev, Kh. M.; Kucherov, A. V. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1990 , vol. 39, # 8.1 p. 1551 - 1555 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1990 , # 8 p. 1713 - 1717