1. S. N. Koikov and A. N. Tsikin, Electrical Aging of Solid Dielectrics (Energiya, Leningrad, 1968) [in Russian].
2. Electrical Properties of Polymers, Ed. by B. I. Sazhin (Khimiya, Leningrad, 1977) [in Russian].
3. M. S. Dakhiya, V. A. Zakrevskii, and A. I. Slutsker, Sov. Phys. Solid State 29 (12), 2070 (1987).
4. T. M. Veliev, Candidate’s Dissertation (Institute of Physics, Azerbaijan National Academy of Sciences, Baku, 1986).
5. M. S. Dakhiya, V. A. Zakrevskii, and A. I. Slutsker, Sov. Phys. Solid State 28 (9), 1513 (1986).