Hendriyan, Fiet. “Trucking System VS. Conveyor System for Coal Material Transportation in PT. Bukit Asam Coal Mines”. Indonesian Interdisciplinary Journal of Sharia Economics (IIJSE) 8, no. 3 (December 31, 2025): 15521-15534. Accessed September 19, 2026. https://e-journal.uac.ac.id/index.php/iijse/article/view/8188.