1. M. M. Godneva, A. T. Belyaevskii, and O. A. Zalkind, Russ. J. Inorg. Chem. 57, 1610 (2012).
2. M. M. Godneva, N. N. Boroznovskaya, N. L. Mikhailova, and O. A. Zalkind, Russ. J. Inorg. Chem. (in press).
3. The Powder Diffraction File (International Centre for Diffraction Data).
4. M. Wloka, S. I. Troyanov, and E. Kemnitz, Solid State Chem. 135, 293 (1998).
5. The Atlas of Infrared Spectra of Phosphates. Orthophosphates, V. V. Pechkovskii, R. Ya. Mel’nikova, and E. D. Dzyuba (Nauka, Moscow, 1981) [in Russian].