1. Continuation theorems for periodic perturbations of autonomous systems;Capietto;Trans. Amer. Math. Soc.,1992
2. Fixed Points and Topological Degree in Nonlinear Analysis;Cronin,1964
3. Fixed Point Theory;Granas,2003
4. Differential Topology;Hirsch,1988
5. Geometric Methods of Nonlinear Analysis;Krasnoselʼskii,1984