Cyclicity and local structural stability of piecewise vector fields
Polycycles in planar vector fields: cyclicity and related problems
Dulac's Problem and of the Focus Center on Two-Dimensional Manifolds
On limit cycles in piecewise linear vector fields with algebraic discontinuity var...
Piecewise Holomorphic Systems and Regularization of Filippov fields around degener...
Synchrony in coupled systems: a connection between graphs and singularities