1. G. V. Vinogradov, A. Ya. Malkin, N. V. Prozorovskaya, and V. A. Kargin, Dokl. Akad. Nauk SSSR,150, 3 (1963).
2. J. D. Ferry, Viscoelastic Properties of Polymers, Wiley, New York (1961).
3. Yu. V. Zelenev and A. G. Novikov, Mekhan. Polim., No. 2, 234 (1966).
4. A. V. Tobolsky, Properties and Structure of Polymers, Wiley, New York (1960).
5. A. P. Aleksandrov and Yu. S. Lazurkin, Zh. Tekh. Fiz.,9, 1249 (1939).