1. Proof of a theorem of A.N. Kolmogorov on the preservation of conditionally periodic motions under a small perturbation of the Hamiltonian;Arnold;Uspekhi Mat. Nauk,1963
2. Mathematical Methods of Classical Mechanics;Arnold,1989
3. Dynamical Systems. III;Arnold,1988
4. Dynamical Systems;Birkhoff,1927
5. Stability of the triangular Lagrangian points;Deprit;Astronom. J.,1967