LI, LONG-TU, and SUI SUN CHENG. “GLOBAL ATTRACTIVITY IN A FOUR-TERM RECURRENCE RELATION”. Tamkang Journal of Mathematics 30, no. 3 (May 1, 2021): 223–229. Accessed April 23, 2024. https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4229.