1. E. Yu. Romanova, B. G. Bazarov, R. F. Klevtsova, et al., Zh. Neorg. Khim. 52(5), 815 (2007) [Russ. J. Inorg. Chem. 52 (5), 749 (2007)].
2. B. G. Bazarov, R. F. Klevtsova, O. D. Chimitova, et al., Zh. Neorg. Khim. 51(5), 866 (2006) [Russ. J. Inorg. Chem. 51 (5), 800 (2006)].
3. B. N. Nekrasov, The Fundamentals of General Chemistry (Khimiya, Moscow, 1967) [in Russian].
4. R. P. Rastogi and B. L. Dybey, J. Inorg. Nucl. Chem. 39(12), 2179 (1977).
5. A. W. Steight, J. D. Bierlein, and P. E. Bierstedt, J. Chem. Phys. 62(7), 2826 (1975).