1. Dual variational methods in critical point theory and applications
2. A. Ambrosetti, M. L. Bertotti, Homoclinics for second order conservative systems, in: Partial differential equations and related subjects (Trento, 1990), Pitman Res. Notes Math. Ser., Vol. 269, Longman Sci. Tech., Harlow, 1992, pp. 21--37.
3. Homoclinics solutions for a class of systems of second order differential equations
4. Abstract critical point theorems and applications to some nonlinear problems with “strong” resonance at infinity
5. Existence of Homoclinic Solutions for a Class of Time-Dependent Hamiltonian Systems