1. N. Bjerrum, Bull. Soc. Chim. Belg. 57, 432 (1948).
2. H. Chateau, M. C. Gadet, and J. Pouradier, J. Chim. Phys. Phys.-Chim. Biol. 63, 269 (1966).
3. I. V. Mironov and L. D. Tsvelodub, Zh. Neorg. Khim. 45(4), 706 (2000) [Russ. J. Inorg. Chem. 45 (4), 633 (2000)].
4. B. I. Peshchevitskii, V. I. Belevantsev, and N. V. Kurbatova, Zh. Neorg. Khim. 16(7), 1898 (1971).
5. V. I. Belevantsev, A. P. Ryzhikh, E. V. Makotchenko, and V. I. Malkova, Zh. Neorg. Khim. 44(4), 608 (1999) [Russ. J. Inorg. Chem. 44 (4), 554 (1999)].