1. D. V. Anosov, "Geodesic flows on closed Riemann manifolds of negative curvature," Trudy Matem. Inst. im. V. A. Steklov,90 (1967).
2. D. V. Anosov and Ya. G. Sinai, "Some smooth ergodic systems," Usp. Matem. Nauk,22, No. 5, 107?172 (1967).
3. E. Hille and R. S. Phillips, Functional Analysis and Semi-Groups, Am. Math. Soc., Providence, R. I. (1957).
4. G. A. Margulis, "Applications of ergodic theory to the investigation of manifolds of negative curvature," Funktsional'. Analiz i Ego Prilozhen.,3, No. 4, 89?90 (1969).
5. V. A. Rokhlin, "Lectures on the entropic theory of measure-preserving transformations," Usp. Matem. Nauk,22, No. 5, 3?56 (1967).