1. The existence of equilibrium states of thin elastic shells (I);Berger;Indiana Univ. Math. J.,1971
2. Topology From the Differential Point of View;Milnor,1965
3. Algebraic Topology;Spanier,1966
4. Nonlinear Functional Analysis, Lecture Notes;Schwartz,1965
5. Topological Methods in the Theory of Nonlinear Integral Equations;Krasnoselski,1965