1. Gorokhovatskii, Yu.A. and Bordovskii, G.A., Termoaktivatsionnaya tokovaya spektroskopiya (Thermal Activation Current Spectroscopy), Moscow: Nauka, 1991.
2. Zakharov, N.A., Orlovskii, V.P., Klyuev, V.A., and Toporov, Yu.P., Neorgan. Mater., 2001, vol. 37, no. 8, p. 1017.
3. Zakharov, N.A., Pis’ma Zh. Tekh. Fiz., 2001, vol. 27, no. 24, p. 22.
4. Dorozhkin, S.V., J. Mater. Sci., 2007, vol. 42, p. 1061.
5. Smolegovskii, A.M., Istoriya kristallokhimii fosfatov (History of Phosphate Crystallochemistry), Moscow: Nauka, 1986.