1. Kittel, Ch. 1978.An Introduction to Solid State Physics, 789Moscow: Nauka.
2. Perova, E. B., Khrameyeva, N. P. and Venevtsev, Yu. N. 1975.Scientific-Technical Prognoses in the Field of CatalysisCorrosion and Synthesis of Ferroelectric Materials, 184Moscow: NIITEHIM.
3. Rado, G. T. and Suhl, H. E. 1966.Magnetism, vol. II B, 206–214. New York-London: Academic Press.
4. Harrison, W. 1972.Theory of Solid, 616Moscow: Mir.
5. Birman, J. R. 1975.Abstr. of Intern. conf. on Low Lying Latt. Vibr. Modes and their Relationship to Supercond. and Ferroelectr.36Puerto-Rico