Johnny Henderson & Rodica Luca 
Boundary Value Problems for Second-Order Finite Difference Equations and Systems [PDF ebook] 

This is an indispensable reference for those mathematicians that conduct research activity in applications of fixed-point theory to boundary value problems for nonlinear difference equations. Coverage includes second-order finite difference equations and systems of second-order finite difference equations subject to diverse multi-point boundary conditions, and various methods to study the existence of positive solutions for these problems.