1. S. Krzewska, H. Podsiadly, and L. Paidovski,J. Inorg. Nucl. Chem. 42, 89 (1980).
2. O. I. Hotsenovskii, V. M. Lebedovskikh, and V. K. Molodtsova,Zhurnal Obschei himii. 44, 72 (1974).
3. J. G. Frost, M. B. Lawson, and W. G. Pherson,Inorg. Chem. 15, 940 (1976).
4. T. D. Gornostaeva, D. D. Khmelnitskaia, S. V. Shmargun, A. F. Panchenko, and V. V. Lodeischikov,Zhurnal neorganicheskoi khimii. 32, 1622 (1987).
5. V. M. Shulman and Z. A. Saveljeva,Izv. Sib. Otd. AN SSSR. 4, 124 (1970).