1. Monotone Iterative Techniques for Discontinuous Nonlinear Differential Equations;Heikkila,1994
2. A boundary value problem for operator equations in Hilbert spaces;Karakostas;J. Math. Anal. Appl.,2000
3. Differential Equations in Abstract Spaces;Ladas,1972
4. Boundary and periodic value problems for differential systems via Sperner's lemma;Palamides;Math. Japonica,1989
5. Some properties of convex sets related to fixed point theorems;Fan;Math. Ann.,1984