1. Homoclinic orbit to a center manifold,;P. Bernard;Calc. Var.,2003
2. Homoclinic orbits in families of hypersurfaces with hyperbolic periodic orbits,;P. Bernard;J. Differential Equations,2002
3. Homoclinic orbits near saddle-center fixed points of Hamiltonian systems with two degrees of freedom,;P. Bernard;Geometric Methods in Dynamics (I) - Volume in honor of Jacob Palis,2003
4. Dynamical Systems,;G. D. Birkhoff;A.M.S. Coll. Publications,1927
5. Twist mappings, linking, analyticity, and periodic solutions which pass close to an unstable periodic solution,;C. Conley;in Topological Dynamics (Sympos,1967