1. Cours de Mécanique Céleste, Tome I;Andoyer,1923
2. Mathematical Aspects of Classical and Celestial Mechanics;Arnold,2006
3. Dynamical Systems;Birkhoff,1927
4. Asymptotic Methods in the Theory of Non-Linear Oscillations;Bogoliubov,1961
5. Methods of Celestial Mechanics;Brouwer,1961