D'yakov,V.M. et al. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1978 , vol. 27, # 10 p. 2098 - 2104 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1978 , vol. 27, # 10 p. 2366 - 2372