1. Difference Equations and Inequalities;Agarwal,1992
2. Advanced Topics in Difference Equations;Agarwal,1997
3. An Introduction to Difference Equations;Elaydi,1996
4. Finite Differences and Difference Equations in the Real Domain;Fort,1948
5. Oscillatory second order linear difference equations and Riccati equations;Hooker;SIAM J. Math. Anal.,1987