1. On the inversion of some differentiable mappings with singularities between Banach spaces;Ambrosetti;Ann. Mat. Pura Appl.,1972
2. A multiplicity result for a class of nonlinear boundary value problems of the Ambrosetti-Prodi type;Basile;Ann. Univ. Ferrara Sez. VII (NS),1980
3. On the solutions of a nonlinear Dirichlet problem;Berger;Indiana Univ. Math. J.,1975
4. Variational methods and sub and super-solutions;Chang;Sci. Sinica Ser. A,1983
5. Lectures on boundary-value problems of the Ambrosetti-Prodi type;De Figueiredo,1980