REFERENCES
[1] R. P. Agarwal, D. O’Regan, Boundary value problems for discrete equations, Appl. Math.
Letters, 10 (1997), 83–89.
[2] R. P. Agarwal, D. O’Regan, P. J. Y. Wong, Positive solutions of differential, difference and
integral equations, Kluwer Acad. Publ. Dordrecht, 1999.
[3] R. P. Agarwal, M. Bohner, P. J. Y. Wong, Positive solutions and eigenvalues of conjugate
boundary-value problems, Proc. Edinburgh Math. Soc. 42 (1999), 349–374.
[4] R. P. Agarwal, D. O’Regan, Nonpositive discrete boundary value problems, Nonlinear Anal.
39 (2000), 207–215
[5] R. P. Agarwal, H. L¨u, D. O’Regan, Eigenvalues and the One-Dimensional p-Laplacian, J.
Math. Anal. Appl. 266 (2002), 383–400.
[6] R. P. Agarwal, K. Perera, D. O’Regan, Multiple positive solutions of singular and nonsingular
discrete problems via variational methods, Nonlinear Anal. 59 (2004), 69–73.
[7] R. P. Agarwal, K. Perera, D. O’Regan, Multiple positive solutions of singular discrete pLaplacian
problems via variational methods, Adv. Difference Equations, 2 (2005), 93–99.
[8] R. P. Agarwal, D. O’Regan, P. J. Y. Wong, Constant-sign solutions of a system of Fredholm
integral equations, Acta Appl. Math. 80 (2004), 57–94.
[9] R. Avery, J. Henderson, Existence of three positive pseudo-symmetric solutions for a one
dimensional discrete p-Laplacian, J. Difference Equ. Appl. 10 (2004), 529–539.
[10] J. Chu, D. Jiang, Eigenvalues and discrete boundary value problems for the one-dimensional
p-Laplacian, J. Math. Anal. Appl. 305 (2005), 452–465.
[11] J. Chu, Z. Zhou, Positive solutions and eigenvalues of nonlocal boundary value problems,
Electron. J. Differential Equations, 86 (2005), 1–9.
[12] J. Chu, H. Chen, D. O’Regan, Positive periodic solutions and eigenvalue intervals for systems
of second order differential equations, preprint.
[13] D. Franco, E. Liz, P. J. Torres, Existence of periodic solutions for population models with
periodic delay, preprint.
[14] D. Franco, G. Infante, D. O’Regan, Nontrivial solutions in abstract cones for Hammerstein
integral systems, Dynam. Contin. Discrete Impuls. Systems, to appear.
[15] D. Jiang, J. Chu, D. O’Regan, R. P. Agarwal, Positive solutions for continuous and discrete
boundary value problems to the one -dimension p-Laplacian, Math. Inequal. Appl. 4 (2004),
523–534.
[16] D. Jiang, L. Zhang, D. O’Regan, R. P. Agarwal, Existence theory for single and multiple
solutions to singular positone discrete Dirichlet boundary value problems to the one-dimension
p-Laplacian, Arch. Math. 40 (2004), 367–381.
[17] M. A. Krasnosel’skii, Positive Solutions of Operator Equations, Noordhoff, Groningen, 1964.
[18] K. Q. Lan, Mulpiple positive solutions of semilinear differential equations with singularities,
J. London Math. Soc. 63 (2001), 690–704.
[19] D. O’Regan, H. Wang, Positive periodic solutions of systems of second ordinary differential
equations, Positivity, in press.
[20] H. Wang, On the number of positive solutions of nonlinear systems, J. Math. Anal. Appl. 281
(2003), 287–306.
[21] H. Wang, Positive periodic solutions of functional differential equations, J. Differential Equations,
202 (2004), 354–366.