1. S. Kapoor, H. B. George, A. Betzen, M. Aatigato, and S. Feller, J. Non-Cryst. Solids 270, 215 (2000).
2. A. A. Kiprianov and N. G. Karpukhina, Fiz. Khim. Stekla 32(1), 3 (2006).
3. A. A. Kiprianov and N. G. Karpukhina, Proc. III Sci. Session UNTsKh, St. Petersburg (St. Petersburg, 2004), p. 70.
4. B. P. Sobolev, The Rare Earth Trifluorides (Institute of Crystallography, Moscow, 2000; Institut d’Estudis Catalans, Barcelona, 2000).
5. I. I. Buchinskaya and P. P. Fedorov, Usp. Khim. 73(4), 404 (2004).