1. Ahlfors LV (1978) Complex analysis. An introduction to the theory of analytic functions of one complex variable. In: International series in pure and applied mathematics, 3rd edn. McGraw-Hill Book Co, New York, xi+331 pp
2. Arnold VI (1963a) Proof of a Theorem by A. N. Kolmogorov on the invariance of quasi-periodic motions under small perturbations of the Hamiltonian. Russ Math Surv 18:13–40
3. Arnold VI (1963b) Small divisor problems in classical and celestial mechanics. Russ Math Surv 18:85–191
4. Arnold VI (1964) Instability of dynamical systems with many degrees of freedom. (Russian). Dokl Akad Nauk SSSR 156:9–12
5. Arnold VI (1974) Mathematical methods of classical mechanics. Series: Graduate texts in mathematics, vol 60. Originally published by Nauka, Moscow, 1974 2nd ed. 1989. Corr. 4th printing, 1997, XVI, 509