Bifurcational Aspects of Parametric Resonance -- 1. Setting of the Problem -- 2. A Normal Form Theory -- 3. Computation of a Third-Order Normal Form -- 4. The Planar Hamilton Form -- 5. Dynamical Conclusions -- A Survey of Normalization Techniques Applied to Perturbed Keplerian Systems -- 1. Introduction -- 2. Perturbed Keplerian Systems -- 3. Normal Form: Theory -- 4. Normal Form: Practice -- 5. Reduction to One Degree of Freedom -- 6. Analysis of Normalized Hamiltonian -- 7. Appendix 1 -- 8. Appendix 2 -- References -- On Littlewood's Counterexample of Unbounded Motions in Superquadratic Potentials -- 1. Introduction -- 2. Results -- 3. Proof of the Theorem -- References -- Center Manifold Theory in Infinite Dimensions -- 1. Introduction -- 2. General Theory -- 3. Spectral Theory -- 4. Examples -- 5. Application to Hydrodynamic Stability Problems -- References -- Oscillations in Singularly Perturbed Delay Equations -- 1. Difference Equations -- 2. Singular Perturbations of Difference Equations with Continuous Argument: Simplest Properties -- 3. Continuous Dependence on a Paramete -- 4. Impact of Singular Perturbations: Examples -- 5. Attractors of Interval Maps and Asymptotic Behavior of Solutions -- 6. Existence of Periodic Solutions -- 7. Concluding Remarks and Open Questions -- References -- Topological Approach to Differential Inclusions on Closed Subsets of ?n -- 1. Multivalued Mappings -- 2. Topological Degree of Admissible Mappings in ?n -- 3. Aronszajn's Result -- 4. Selectionable and ?-Selectionable Multivalued Maps -- 5. Differential Inclusions in ?n -- 6. Periodic Solutions of Differential Inclusions in ?n -- 7. Sets with Property p -- 8. Contingent Cone Valued Maps -- 9. Differential Inclusions on Sets with Property p -- 10. Proof of Lemma (7.3) -- References.