Averaging Theory for studying the periodic solutions of the differential systems a...
Invariant Sets in differential Dynamical Systems: Periodic orbits, Invariant Tori ...
Qualitative theory of ordinary differential equations: integrability, periodic orb...
Averaging theory for finding periodic solutions of Carathéodory differential equat...
The method of guiding functions for differential equations and inclusions
Topological methods in the study of periodic solutions of non-smooth differential ...