1. Theory of Functional Differential Equations;Hale,1977
2. Oscillations in Planar Dynamic Systems;Mickens,1996
3. Nonlinear Oscillations Dynamical Systems and Bifurcations of Vector Fields;Guckenheimer,1983
4. Applications of Qualitative Methods of Ordinary Differential Equations;Ding,2004
5. Analysis of bifurcation and chaos in double-well Duffing system via Laguerre polynomial approximation;Ma;Acta Phys. Sin.,2006