Tyuleneva,V.V. et al. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1975 , vol. 24, p. 1042 - 1045 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1975 , vol. 24, # 5 p. 1136 - 1139