Saddle points and multiple solutions of differential equations

This publication has 21 references indexed in Scilit:

• Some applications of monotone operator theory to resonance problems
  Nonlinear Analysis, 1979
• Hammerstein integral equations with indefinite kernel
  International Journal of Mathematics and Mathematical Sciences, 1978
• Forced vibrations for a nonlinear wave equation
  Communications on Pure and Applied Mathematics, 1978
• Nichtlineare Gleichungen und Abbildungsgrade
  Published by Springer Nature ,1974
• Dual variational methods in critical point theory and applications
  Journal of Functional Analysis, 1973
• A Variant of the Lusternik-Schnirelman Theory
  Indiana University Mathematics Journal, 1972
• A minimum-maximum principle for a class of non-linear integral equations
  Journal d'Analyse Mathématique, 1969
• Periodic solutions of a weakly nonlinear wave equation in one dimension
  Czechoslovak Mathematical Journal, 1969
• Topological Methods in the Theory of Nonlinear Integral Equations.
  The American Mathematical Monthly, 1968
• Periodic Solutions of Nonlinear Hyperbolie Partial Differential Equations
  Communications on Pure and Applied Mathematics, 1967