1. F. Balibrea, R. Chacón, and, M. A. López, Some bifurcations in uniparametric families of elliptic maps, Internat. J. Bifur. Chaos Appl. Sci. Engrg, to appear.
2. Applications of Center Manifold Theory;Carr,1981
3. On bifurcations of maps of the interval;Guckenheimer;Invent. Math.,1977
4. Nonlinear Oscillations, Dynamical Systems and Bifurcations of Vector Fields;Guckenheimer,1983
5. Dynamics and Bifurcations;Hale,1991