Ueber Relationen, welche für die zwischen je zwei singulären Punkten erstreckten Integrale der Lösungen linearer Differentialgleichungen stattfinden.
Ueber Relationen zwischen hypergeometrischen Integralen nter Ordnung.
Unbounded basins of attraction of limit cycles.
Uniformly isochronous polynomial centers.
Uniqueness of limit cycles bounded by two invariant parabolas
In this paper we consider a class of cubic polynomial systems with two invariant parabolas and prove in the parameter space the existence of neighborhoods such that in one the system has a unique limit cycle and in the other the system has at most three limit cycles, bounded by the invariant parabolas.
Uniqueness of limit cycles for a class of cubic systems with two invariant straight lines.