1. I. S. Rez and Yu. M. Poplavko, Dielectrics: Fundamental Properties and Applications in Electronics (Radio i Svyaz’, Moscow, 1989) [in Russian].
2. M. Lains and A. Glass, Principles and Applications of Ferroelectrics and Related Materials (Oxford University Press, Oxford, 1977; Mir, Moscow, 1981).
3. G. A. Lusheĭkin, Polymer Electrets (Khimiya, Moscow, 1984) [in Russian].
4. K. L. Ng, H. L. W. Chan, and C. L. Choy, IEEE Trans: Ultrason., Ferroelectr., Freq. Control 47, 1308 (2000).
5. C. W. Nan and G. J. Weng, J. Appl. Phys. 88, 416 (2000).