Nagapetyan, S. S.; Arakelova, A. R.; Ziger, E. A.; Koshkin, V. M.; Struchkov, Yu. T.; Shklover, V. E. Russian Journal of Inorganic Chemistry (Translation of Zhurnal Neorganicheskoi Khimii), 1989 , vol. 34, p. 1276 - 1280 Zhurnal Neorganicheskoi Khimii, 1989 , vol. 34, p. 2244 - 2249