1. B. P. Sobolev, The Rare Earth Trifluorides, Part 1: The High Temperature Chemistry of the Rare Earth Trifluorides (Institute of Crystallography, Moscow, 2000; Institut d’Estudis Catalans, Barcelona, 2000) (www.books.google.ru/books/rare earth trifluorides).
2. B. P. Sobolev, The Rare Earth Trifluorides, Part 2: Introduction to Materials Science of Multicomponent Metal Fluoride Crystals (Institute of Crystallography, Moscow, 2001; Institut d’Estudis Catalans, Barcelona, 2001) (www.books.google.ru/books/rare earth trifluorides).
3. B. P. Sobolev, Crystallogr. Rep. 57 (3), 434 (2012).
4. G. A. Bandurkin, Geokhimiya 1 (1), 3 (1964).
5. G. A. Bandurkin, Izv. Akad. Nauk SSSR, Neorg. Mater. 1 (9), 1569 (1965).