1. N. N. Bogolyubov, ?Problems of a dynamical theory in statistical physics?, in: Studies in Statistical Mechanics, Vol. 1, J. de Boer and G. E. Uhlenbeck (editors), North-Holland, Amsterdam (1962).
2. J. Weinstock, Phys. Rev.,132, 454, 470 (1963).
3. R. Goldman and E. A. Frieman, Bull. Amer. Phys. Soc., 10, 531 (1952); J. Math. Phys.,8, 1410 (1967).
4. J. R. Dorfman and E. G. D. Cohen, Phys. Lett.,16, 124 (1965); J. Math. Phys.,8, 282 (1967).
5. I. Prigogine, Proceeding of the Phys. Session Int. School of Nonlinear Math. and Phys., Springer, New York (1966).