1. 1) A. S. Nowick and B. S. Berry: Anelastic Relaxation in Crystalline Solids, Pergamon Press, New York, (1972), p. 454.
2. 2) J. Woirgard, J. P. Amirault and J. de Fouquet: Proc. ICIFUAS 5, ed. by D. Lenz and K. Lücke, Springer-Verlag, Berlin, Vol. I, (1975), p. 392.
3. 3) G. Schoeck, E. A. Bisogni and J. Shyne: Acta Metall., 12 (1964), 1466.
4. 4) B. YA. Pinès and A. A. Karmazin: Fiz. metal. metalloved., 22 (1966), 632.
5. 5) I. G. Ritchie and K. W. Sprungmann: Atomic Energy of Canada Limited Report, AECL-6810, (1981).