1. Upper and lower solutions in the theory of ODE boundary value problems: Classical and recent results;De Coster,1996
2. Monotone Iterative Techniques for Discontinuous Nonlinear Differential Equations;Heikkilä,1994
3. Monotone methods for a discrete boundary problem;Zhuang;Computers Math. Applic.,1996
4. Focal boundary value problems for differential and difference equations;Agarwal,1998
5. Upper and lower solutions method for higher-order discrete boundary value problems;Agarwal;Math. Inequal. Appl.,1998