1. Discrete Hamiltonian Systems: Difference Equations, Continued Fractions, and Riccati Equation;Ahlbrandt,1996
2. Difference Equations and Inequalities, Theory, Methods and Applications;Agarwal,2000
3. Discrete trigonometric matrix functions;Anderson;Panamer. Math. J.,1997
4. Discrete and Continuous Boundary Value Problems;Atkinson,1964
5. Generalized Inverses: Theory and Applications;Ben-Israel,2003