1. M. V. Mokhosoev, F. P. Alekseev, and V. L. Butukhanov,Binary Molybdates and Tungstates [in Russian], Nauka, Novosibirsk (1981).
2. V. K. Trunov, V. A. Efremov, and Yu. A. Velikodnyi,Crystal Chemistry and Properties of Binary Molybdates and Tungstates [in Russian], Nauka, Leningrad (1986).
3. M. V. Mokhosoev and Zh. G. Bazarova,Complex Molybdenum and Tungsten Oxides with Group I-IV Elements [in Russian], Nauka, Moscow (1990).
4. J. A. Ibers and G. W. Smith,Acta Crystallogr.,17, No. 2, 190–197 (1964).
5. L. Katz, A. Kazenally, and L. Kihlborg, ——ibid.,B27, No. 11, 2071–2077 (1971).