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2. Infinite Dimensional Morse Theory and Multiple Solution Problems;Chang,1993
3. Cohomology and Morse theory for strongly indefinite functionals;Szulkin;Math. Z.,1992
4. Equivariant Morse theory for isolated critical orbits and its applications to nonlinear roblems;Wang,1988
5. Isolated invariant sets and the Morse index;Conley,1978