REFERENCES
[1] R. P. Agarwal, D. O’Regan and P. J. Y. Wong, Positive Solutions of Differential, Difference
and Integral Equations, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1999.
[2] R. I. Avery, A generalization of the Leggett–Williams fixed point theorem, Math. Sci. Res.
Hot-line, 3 (1999), 9–14.
[3] X. Cheng and C. Zhang, Existence of positive solutions for a second order differential system,
J. Math. Anal. Appl., 312 (2005), 14–23.
[4] K. Deimling, Nonlinear Functional Analysis, Springer, New York, 1985.
[5] P. W. Eloe and J. Henderson, Positive solutions for (n − 1, 1) conjugate boundary value problems,
Nonlinear Anal., 28 (1997), 1669–1680.
[6] L. H. Erbe and H. Wang, On the existence of positive solutions of ordinary differential equations,
Proc. Amer. Math. Soc., 120 (1994), 743–748.
[7] J. Henderson and S. K. Ntouyas, Positive solutions for system of nth order three-point nonlocal
boundary value problems, Elec. J. Qual. Theory Diff. Equ., 2007 (2007), no. 18, 1–12.
[8] J. Henderson and S. K. Ntouyas, Positive solutions for systems of three-point nonlinear boundary
value problems, Aust. J. Math. Anal. Appl., 5 (2008), 1–9.
[9] J. Henderson and S. K. Ntouyas, Positive solutions for systems of nonlinear boundary value
problems, Nonlinear Stud., 15 (2008), 51–60.
[10] J. Henderson, S. K. Ntouyas and I. K. Purnaras, Positive solutions for systems of generalized
three-point nonlinear boundary value problems, Comment. Math. Univ. Carolin., 49 (2008), 79–91.
[11] L. Hu and L. Wang, Multiple positive solutions of boundary value problems for systems of
nonlinear second-order differential equations, J. Math. Anal. Appl., 335 (2007), no. 2, 1052– 1060.
[12] R. W. Leggett and L. R. Williams, Multiple positive fixed points of nonlinear operator on
order Banach spaces, Indiana Univer. Math. J., 28 (1979), 673–688.
[13] L. Liu, P. Kang and Y. Wu, Positive solutions of singular boundary value problems for systems
of nonlinear fourth order differential equations, Nonlinear Anal., 68 (2008), 485–498.
[14] Y. Liu and B. Yan, Multiple solutions of singular boundary value problems for differential
systems, J. Math. Appl. Anal., 287 (2003), 40–55.
[15] R. Ma, Multiple nonnegative solutions of second order systems of boundary value problems,
Nonlinear Anal., 42(2000), 1003–1010.
[16] K. R. Prasad, P. Murali and A. K. Rao, Multiple positive solutions for the system of higher
order two-point boundary value problems, Pan Amer. Math. J., 19 (2009), no. 2, 63–73.
[17] J. Xu and Z. Yang, Positive solutions for a system of nth-order nonlinear boundary value
problems, Elec. J. Qual. Theory Diff. Equ., 2011 (2011), no. 4, 1–16.