Ilmi, Fiqrhatul, and Mawardi Mawardi. “Effect of Concentration Sulfuric Acid on Alumina Extraction from Napa Soil”. Jurnal Pijar Mipa 18, no. 5 (September 30, 2023): 766–770. Accessed November 22, 2024. http://jurnalfkip.unram.ac.id/index.php/JPM/article/view/5546.