Panggabean, J. F. R., O. S. Sitompul, and E. B. Nababan. “The Flowshop Scheduling Makespan by the ACO-GA Algorithm: The Flowshop Scheduling Makespan by the ACO-GA Algorithm”. Jurnal Mantik, vol. 3, no. 4, Feb. 2020, pp. 743-9, https://iocscience.org/ejournal/index.php/mantik/article/view/710.