1. [1] R. P. Agarwal, “Compactness condition for boundary value problems”, pp. 1–23 in Proceedings conference on differential equations and applications (Brno, 1997), EQUDIFF 9, 1998.
2. [2] S. Clark and J. Henderson, “Uniqueness implies existence and uniqueness criterion for nonlocal boundary value problems for third order differential equations”, Proc. Amer. Math. Soc. 134:11 (2006), 3363–3372.
3. [3] E. A. Coddington and N. Levinson, Theory of ordinary differential equations, McGraw–Hill, New York, 1955.
4. [4] S. D. Conte, Elementary numerical analysis: An algorithmic approach, 3rd ed., McGraw–Hill, New York, 1981.
5. [5] W. A. Coppel, Disconjugacy, Lecture Notes in Mathematics 220, Springer, New York, 1971.