Gol'dfarb,Ya.L. et al. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation)Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 19781978, vol. 2727, # 12 p. 2462 - 24692760 - 2767 doi: 10.1007/BF00941097