Cherstkov, V. F.; Sterlin, S. R.; German, L. S.; Knunyants, I. L. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1982 , vol. 31, # 12 p. 2472 - 2474 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1982 , # 12 p. 2796 - 2798