“Analisis Pengaruh Perubahan Nilai Total Moisture Dan Ash Content Terhadap Nilai Kalori Batubara Di Unit Pelabuhan Pt Bukit Asam Tbk Tarahan Bandar Lampung”. MINERAL 5, no. 1 (April 1, 2020): 7–12. Accessed April 19, 2026. https://www.journal.ubb.ac.id/index.php/mineral/article/view/3053.