Ismailov,R.D. et al. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1973 , vol. 22, # 4 p. 788 - 792 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1973 , vol. 22, # 4 p. 810 - 816