1. Ordinary Differential Equations;Hale,1969
2. Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields;Guckenheimer,1983
3. Van der Pol's oscillator under delayed feedback;Atay;Journal of Sound and Vibration,1998
4. Oscillations in a Van der Pol equation with delayed argument;de Oliveira;Journal of Mathematical Analysis and Applications,2002
5. Theory of Functional Differential Equations;Hale,1977