Lebedev, S. A.; Sorokina, R. S.; Berestova, S. S.; Petrov, E. S.; Beletskaya, I. P. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1986 , vol. 35, # 3 p. 620 - 622 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1986 , # 3 p. 679 - 681