THANDAPANI, E., and S. PANDIAN. “OSCILLATION THEOREMS FOR NONLINEAR SECOND ORDER DIFFERENCE EQUATIONS WITH A NONLINEAR DAMPING TERM”. Tamkang Journal of Mathematics 26, no. 1 (March 1, 1995): 49–58. Accessed April 25, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4378.