1. P. O. Andreev, E. I. Salnikova, and A. A. Kislitsyn, Russ. J. Phys. Chem. 87, 1482 (2013).
2. E. I. Salnikova, D. I. Kaliev, and P. O. Andreev, Russ. J. Phys. Chem. 85, 2121 (2011).
3. V. V. Serebrennikov and L. A. Alekseenko, Lectures on the Chemistry of Rare-Earth Elements (TGU, Tomsk, 1963) [in Russian].
4. V. A. Batyreva, V. V. Kozik, V. V. Serebrennikov, and G. M. Yakunina, Syntheses of Rare-Earth Compounds (TGU, Tomsk, 1983) [in Russian].
5. Yu. D. Tret’yakov, L. I. Martynenko, A. N. Grigor’ev, and A. Yu. Tsivadze, Inorganic Chemistry. The Chemistry of the Elements: Textbook for High Schools (Khimiya, Moscow, 2001), Book 1 [in Russian].