1. Difference Equations and Inequalities: Theory, Methods and Applications;Agarwal,2000
2. An Introduction to Difference Equations;Elaydi,1999
3. Global Behavior of Nonlinear Difference Equations of Higher Order with Applications;Kocic,1999
4. Oscillation Theory of Delay Differential Equations;Györi,1991
5. Asymptotic behavior of solutions of first order nonlinear delay difference equations;Chen;Comput. Math. Appl.,1996