Infinitely many critical points for functionals which are not even and applications to superlinear boundary value problems

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Natural Sciences, Mathematics, Physics +14

Topological Methods in the Theory of Nonlinear Integral Equations.

E. H. Rothe, M. A. Krasnosel’skii, A. H. Armstrong et al. · American Mathematical Monthly · 1968 · 2K citations

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David Clark · Indiana University Mathematics Journal · 1972 · 313 citations

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A generalized Morse theory

Richard S. Palais, Stephen T. Smale · Bulletin of the American Mathematical Society · 1964 · 300 citations · Full text

Natural Sciences, Mathematics, Computational Geometry +12

Characteristic values associated with a class of nonlinear second-order differential equations

Zeev Nehari · Acta Mathematica · 1961 · 237 citations

Natural Sciences, Mathematics, Differential Equations +10