et. al, Cecilia E. Nugraheni. “A Tabu Search Based Hyper-Heuristic for Flexible Flowshop Scheduling Problems”. International Journal of Advanced Science and Technology 29, no. 2 (January 13, 2020): 301 - 310. Accessed September 28, 2021. https://sersc.org/journals/index.php/IJAST/article/view/3185.