1. Critical points and nonlinear variational problems;Ambrosetti;Mem. Soc. Math. France (N.S.),1992
2. Homoclinics for second order conservative systems;Ambrosetti,1992
3. Multiple homoclinic orbits for a class of conservative systems;Ambrosetti;Rend. Sem. Math. Univ. Padova,1993
4. Dynamical Systems III;Arnold,1985
5. Homoclinic orbits on compact manifolds;Benci;J. Math. Anal. Appl.,1991