1. I. V. Tananaev, I. A. Rozanov, K. A. Avduevskaya, et al., Phosphates of Tetravalent Elements (Nauka, Moscow, 1972) [in Russian].
2. M. M. Godneva, D. L. Motov, N. N. Boroznovskaya, and V. M. Klimkin, Zh. Neorg. Khim. 52(5), 725 (2007) [Russ. J. Inorg. Chem. 52 (2), 661 (2007)].
3. Luminescent Materials and Chemicals. Catalog (Cherkassy, 1983) [in Russian].
4. M. M. Godneva, D. L. Motov, and V. Ya. Kuznetsov, Zh. Neorg. Khim. 53(10), 1770 (2008) [Russ. J. Inorg. Chem. 53 (10), 1654 (2008)].
5. The Powder Diffraction File (International Centre for Diffraction Data).