1. A resonance problem in which the nonlinearity may grow linearly;Ahmad,1984
2. A multiplicity result for a class of elliptic boundary value problems;Amann,1979
3. On the inversion of some differentiate mappings with singularities between Banach Spaces;Ambrosetti;Ann. Mat. Pura Appl.,1972
4. Characterizations of the ranges of some nonlinear operators and applications to boundary value problems;Brézis;Ann. Scuola Norm. Sup. Pisa Cl. Sci.,1978
5. Functional analysis and Galerkin's method;Cesari;Michigan Math. J.,1964