1. Discrete and Continuous Boundary Problems;Atkinson,1964
2. Finite Differences and Difference Equations in the Real Domain;Fort,1948
3. Computational aspects of three-term recurrence relations;Gautschi;SIAM Rev.,1967
4. Difference equations: disconjugacy, principal solutions, Green's functions, complete monotonicity;Hartman;Trans. Amer. Math. Soc.,1978
5. On linear difference equations of the second order;Hartman;Amer. J. Math.,1950