We prove the existence of one-signed periodic solutions of second-order nonlinear difference equation on a finite discrete segment with periodic boundary conditions by combining some properties of Green's function with the fixed-point theorem in cones.
"Existence of One-Signed Solutions of Discrete Second-Order Periodic Boundary Value Problems." Abstr. Appl. Anal. 2012 (SI09) 1 - 13, 2012. https://doi.org/10.1155/2012/437912