1. D. V. Anosov, Geodesic flows on closed Riemannian manifolds of negative curvature, Trudy Matem. Inst. AN SSSR,90 (1967).
2. D. V. Anosov and Ya. G. Sinai, Certain ergodic smooth systems, Uspekhi Matem. Nauk,22, No. 5, 107?172(1967).
3. K. Nomidzu, Lie Groups and Differential Geometry [in Russian], Moscow (1960).