American Mathematical Monthly · 1966 · 842 citations · 0 references
Natural SciencesMathematicsComputational MechanicsDifferential EquationsCalculus Of VariationsOperator TheoryPerturbation MethodsVariational FormulationVariational InequalitiesVariational PrinciplesNonlinear Variational FormulationNonlinear Variational ProblemsOperatorsVariational Methods In Partial Differential EquationsVariational Problems