Al-Nassir, Sadiq, and Ghosoon M. Hamoudi. “An Optimal Harvesting of A Discrete Time System With Ricker Growth”. Communications in Mathematics and Applications 10, no. 1 (March 31, 2019): 169–179. Accessed November 22, 2024. http://rgnpublications.com/journals/index.php/cma/article/view/1035.