Abdullah, O. S., S. Abdullah, and H. Mohd Sarim. “Harmony Search Algorithm for the Multiple Runways Aircraft Landing Scheduling Problem”. Journal of Telecommunication, Electronic and Computer Engineering (JTEC), vol. 9, no. 3-7, Nov. 2017, pp. 59-65, https://jtec.utem.edu.my/jtec/article/view/3076.