Hafni Sahir, Syafrida, Joli Afriani, Garuda Ginting, Barany Fachri, Dodi Siregar, Ramadona Simbolon, L Lindawati, et al. “The Preference Selection Index Method in Determining the Location of Used Laptop Marketing”. International Journal of Engineering and Technology 7, no. 3.4 (June 25, 2018): 260–263. Accessed June 8, 2025. https://mail.sciencepubco.com/index.php/IJET/article/view/19869.