1. Introduction to Non-Linear Mechanics: Topological Methods, Analytical Methods, Non-Linear Resonance, Relaxation Oscillations;Minorsky,1947
2. New Methods of Celestial Mechanics, Volume I–III;Poincaré,1957
3. Dynamical Systems;Birkhoff,1991
4. Qualitative Theory of Differential Equations;Nemytskii,1960
5. Topological Dynamics and Ordinary Differential Equations;Sell,1971