“POTENSI LOGAM TANAH JARANG DI DALAM ABU BATUBARA: POTENTIAL OF RARE EARTH METALS IN COAL ASH”. MINERAL 8, no. 2 (December 8, 2023): 1–7. Accessed April 19, 2026. https://www.journal.ubb.ac.id/index.php/mineral/article/view/4364.