1. Morse Theorie für berandete Mannigfaltigkeiten;Braess;Math. Ann.,1974
2. Nonlinear Eigenvalue Problems and Group Invariance in Functional Analysis;Browder,1970
3. A setting for global analysis;Eells;Bull. Amer. Math. Soc.,1966
4. Fredholm structures;Eells,1970
5. Foundations of Algebraic Topology;Eilenberg,1952