1. K. K. Palkina, A. N. Kochetov, E. V. Savinkina, and L. Yu. Alikberova, Zh. Neorg. Khim. 51(11), 1852 (2006) [Russ. J. Inorg. Chem. 51 (11), 1743 (2006)].
2. K. K. Palkina and A. N. Kochetov, Zh. Neorg. Khim. 53(7), 1127 (2008) [Russ. J. Inorg. Chem. 53 (7), 1046 (2008)].
3. L. B. Kigore, J. H. Ford, and W. C. Wolfe, Ind. Eng. Chem. 34(4), 494 (1942).
4. D. Zacharova-Kalavska, I. Zelensky, and A. Perjessy, Chem. Zvesti 23(2), 107 (1969).
5. A. Ahmedova, V. Rusanov, A. Harell, et al., Inorg. Chim. Acta 359, 3123 (2006).