1. Fixed point equations and nonlinear eigenvalue problems in ordered Banach spaces;Amann;SIAM Rev.,1976
2. A. Ambrosetti, G. Prodi, A Primer of Nonlinear Analysis, Cambridge University Press, Cambridge, 1993.
3. Simplicité et isolation de la première valeur propre du p-laplacien avec poids;Anane;C.R. Acad. Sci. Paris Sér. I Math.,1987
4. Sublinear elliptic equations in Ls;Boccardo;Houston, Math. J.,1994
5. Some properties of higher order Sobolev spaces;Brezis;J. Math. Pures Appl.,1982