1. S. N. Koĭkov and A. N. Tsikin, Electrical Aging of Solid Insulators (Énergiya, Leningrad, 1968) [in Russian].
2. M. S. Dakhiya, V. A. Zakrevskiĭ, and A. I. Slutsker, Fiz. Tverd. Tela (Leningrad) 29, 3614 (1987) [Sov. Phys. Solid State 29, 2070 (1987)].
3. V. A. Zakrevskiĭ and N. T. Sudar’, Fiz. Tverd. Tela (St. Petersburg) 47, 931 (2005) [Phys. Solid State 47, 961 (2005)].
4. B. I. Sazhin, Electrical Properties of Polymers (Khimiya, Leningrad, 1970) [in Russian].
5. V. B. Berezhanskiĭ, V. M. Bykov, V. V. Gorodov, et al., Vysokomol. Soedin., Ser. A 28, 2163 (1986).