1. V. S. Grunin, Z. N. Zonn, I. B. Patrina, et al., Problems in the Theoretical Crystal Chemistry of Oxide Compounds [in Russian], Leningrad (1982), pp. 66?90.
2. V. S. Grunin, M. V. Razumeenko, and I. B. Patrina, Abstracts for the 12th Mendeleev Congress on General and Applied Chemistry [in Russian], Part 5, Moscow (1981), p. 175.
3. G. A. Pevtsov, V. Z. Krasil'shchik, and I. I. Egorova, Physicochemical Analysis Methods for Especial-Purity Substances [in Russian], Moscow (1969), pp. 93?107 (Trudy IREA, No. 16).
4. A. I. Staikov and V. S. Kalishevich, Zh. Anal. Khim.,33, No. 4, 213?218 (1978).
5. V. A. Pashkovskaya, Analysis Methods for Electronic-Engineering Materials [in Russian], Moscow (1983), pp. 175?179.