Qualitative study of linear and nonlinear ordinary differential equations
Introduction to the qualitative theory of ordinary differential equations
An introduction to the qualitative theory and bifurcations of dynamical systems
Qualitative methods for ordinary differential equations applied to the study of Li...
The study of periodic orbits in piecewise continuous differential systems
Analysis of Functional Integral Equations, Generalized Ordinary Differential Equat...
Piecewise smooth vector fields: Closing Lemmas, shifts and horseshoe dynamics.