Mastryukova,T.A. et al. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1977 , vol. 26, # 10 p. 2153 - 2157 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1977 , vol. 26, # 10 p. 2317 - 2322