1. [Arn] Arnold, V.I.:Proof of a theorem by A.N. Kolmogorov on the invariance of quasi-periodic motions under small perturbations of the Hamiltonian. Usp. Math. Nauk18, 13?40 (1963); Russ. Math. Surv.18, 9?36 (1963)
2. [Brj] Brjuno, A.D.:Analytic form of differential equations. Trans. Mosc. Math. Soc.25, 131?288 (1971)
3. [CC] Celletti, A., Chierchia, L.:Construction of analytic KAM surfaces and effective stability bounds. Commun. Math. Phys.118, 119?161 (1988)
4. [DRV] Dodson, M.M., Rynne, B.P., Vickers, J.A.G.:Metric diophantine approximation and Hausdorff dimensions on manifolds. Math. Proc. Camb. Philos. Soc. (to appear)
5. [Eli] Eliasson, L.H.:Perturbations of stable invariant tori. Ann. Sc. Norm. Super. Pisa, Cl. Sci., IV. Ser.15, 115?147 (1988)