Gorbunov, D. B.; Voznesenskii, V. N.; Ershov, V. V.; Nikiforov, G. A. Russian Chemical Bulletin, 1994 , vol. 43, # 1 p. 93 - 97 Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1994 , # 1 p. 98 - 102