1. Homotopy extension theorem in Banach spaces and some of its applications to the theory of non-linear equations;Granas;Bull. Acad. pol. Sci.,1959
2. Fixed Point Theory I;Dugundji,1982
3. On the uniqueness of the topological degree;Amann;Math. Z.,1973
4. Degree Theory;Lloyd,1978
5. Compacité monotonie et convexité dans l'étude de problèmes aux limites semi-linéaires;Mawhin,1981