Benekas, Vasileios, and Ardak Kashkynbayev. “A Survey on Sharp Oscillation Conditions for Delay Difference Equations”. Journal of Advances in Applied & Computational Mathematics 8 (March 1, 2022): 117–128. Accessed December 23, 2024. https://avantipublisher.com/index.php/jaacm/article/view/1194.