El'perina, E. A.; Struchkova, M. I.; Serkebaev, M. I.; Serebryakov, E. P.
Russian Chemical Bulletin, 1993 , vol. 42, # 4 p. 744 - 750
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, 1993 , # 4 p. 776 - 781