Discrete Dynamics in Nature and Society
Volume 2009 (2009), Article ID 760328, 9 pages
doi:10.1155/2009/760328
Research Article

Periodic Solutions for a System of Difference Equations

Shugui Kang1,2 and Bao Shi2

1College of Mathematics and Computer Science, Shanxi Datong University, Datong, Shanxi 037009, China
2Department of Basic Sciences, Naval Aeronautical Engineering Institute, Yantai, Shandong 264001, China

Received 9 January 2009; Accepted 8 March 2009

Academic Editor: Guang Zhang

Copyright © 2009 Shugui Kang and Bao Shi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper deals with the second-order nonlinear systems of difference equations, we obtain the existence theorems of periodic solutions. The theorems are proved by using critical point theory.