Existence of Nonnegative and Nonpositive Solutions for Second Order Periodic Boundary Value Problems - Rachůnková, Irena; Tvrdý, Milan; Vrkoč, Ivo (Journal of Differential Equations, 2001)
Keywords: attractive and repulsive singularity; differential inequalities; Duffing equation; lower and upper functions; nonnegative solution; nonpositive solution; periodic solution; second order nonlinear ordinary differential equation; second order nonlinear ordinary differential equation; periodic solution; differential inequalities; attractive and repulsive singularity; nonnegative solution; Duffing equation; lower and upper functions; nonpositive solution