Introduction to the study of limit cycles in planar dynamical systems
Continuous or piecewise smooth dynamical systems on 2 and 3 dimensional manifolds.
On the number of limit cycles bifurcating from a linear center
Qualitative study of linear and nonlinear ordinary differential equations
An introduction to the ordinary diferential equations qualitative theory
Limit cycles of discontinuous piecewise smooth differential systems in the plane R...
Local and global aspects of the qualitative theory of ordinary differential equations