1. V. Ya. Levin and L. A. Kutepova, Izv. Akad. Nauk SSSR, Ser. Geol., No. 4, 90–100 (1975).
2. V. A. Popov and V. I. Popova, Mineralogy of Pegmatites of the Ilmeny Mountains (Mineral. Almanac, Moscow), issue 9 (2006).
3. I. S. Williams, Revs. Econ. Geol. 7, 1–35 (1998).
4. A. A. Krasnobaev, A. I. Rusin, S. V. Busharina, et al., Dokl. Akad. Nauk 430(1), 76–79 (2010).
5. A. A. Krasnobaev, P. M. Valizer, S. V. Busharina, et al., Dokl. Akad. Nauk 452(2), 1008–1013 (2013).