1. P. Ehrenfest and T. Ehrenfest, The Conceptual Foundation of the Statistical Approach in Mechanics (Cornell University Press, Ithaca, 1959).
2. D. Szász, in Hard Ball Systems and the Lorentz Gas (Springer Verlag, Berlin, 2000).
3. Y. G. Sinai, Russ. Math. Surv. 25(2):137 (1970).
4. See the review of N. Simányi in Ref. [2].
5. V. Donnay, Ergodic Theory of Dynamical Systems 16:975 (1996).