Recent results in perturbation theory -- The existence of critical points in generalized dynamical systems -- Stability and existence of periodic and almost periodic solutions -- Asymptotic equivalence -- Extending Liapunovโ{128}{153}s second method to non-lipschitz Liapunov functions -- Characterizing solutions of the pontriagin maximum principle -- Liapunov functions and the existence of solutions tending to 0 -- Fundamental matrix in linear functional differential equations -- Asymptotic stability for functional differential equations -- The use of Liapunov functions for global existence -- A remark on a result of Strauss -- Single species model for population growth depending on past history -- An extension of Chetaevโ{128}{153}s instability theorem using invariant sets and an example