Mohammed, Suad Khairi, Ahmad Afif Mohd Faudzi, Hamdan Daniyal, Badaruddin Muhammad, Nor Azlina Ab. Aziz, Zulkifli Md Yusof, Kamil Zakwan Mohd Azmi, and Asrul Adam. “Improving Black Hole Algorithm Using Gravitational Search, White Hole Operator, and Local Search”. Mekatronika 1, no. 2 (July 1, 2019): 8-14. Accessed November 26, 2020. https://journal.ump.edu.my/mekatronika/article/view/4891.