1. Existence theorems for equations of Hammerstein type;Amann;Appl. Anal.,1972
2. Nonlinearity and Functional Analysis;Berger,1977
3. An abstract existence theorem at resonance;Cesari,1977
4. Functional Analysis and Nonlinear Differential Equations,1976
5. Theory of Ordinary Differential Equations;Coddington,1955