Lermontov, S. A.; Rakov, I. M.; Martynov, I. V. Bulletin of the Academy of Sciences of the USSR, Division of Chemical Science (English Translation), 1990 , vol. 39, # 12 p. 2584 - 2587 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1990 , vol. 39, # 12 p. 2848 - 2851