International Journal of Differential Equations

Volume 2010 (2010), Article ID 598068, 14 pages

doi:10.1155/2010/598068

## Oscillation Criteria for Second-Order Delay, Difference, and Functional Equations

^{1}Department of Mathematics, University of Gjirokastra, 6002 Gjirokastra, Albania^{2}Department of Mathematics, University of Ioannina, 451 10 Ioannina, Greece

Received 2 December 2009; Accepted 9 January 2010

Academic Editor: Leonid Berezansky

Copyright © 2010 L. K. Kikina and I. P. Stavroulakis. 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

Consider the second-order linear delay differential equation