1. P. Debye, “Polar Molecules” (Chemical Catalogue Co., New York, 1929).
2. K. W. Wagner, Ann. Physik 40 (1913) 817.
3. C. Zener, “Elasticity and Anelasticity of Metals” (University of Chicago Press, Chicago, Ill., 1948).
4. H. Rötger, Glastech. Ber. 19 (1941) 192.
5. A. S. Nowick and B. S. Berry, “Anelastic Relaxation in Crystalline Solids” (Academic Press, New York, 1972).