1. Landau, L. and E. M. Lifschitz. Statistical Physics Pergamon Press Ltd., London, Paris, Addison-Wesley Publ. Co. Inc., Reading, U.S.A. (1958) p.350.
2. Nyquist, P. Prog. Theor. Phys., 20, 948 (1958).
3. Kubo, R. (a) J Phys. Soc. Japan, 12, 570 (1957).
4. Lectures Theoret. Phys., (Boulder), 1, 120 (1958).
5. Zwanzig, R. Ann. Rev. Phys. Chem., 16, 67 (1965).