Peningkatan Kadar Tantalum & Niobium Oksida dari Terak Timah Bangka Menggunakan Pelarut NaOH dilanjutkan dengan HNO3 dan H3PO4. Journal of Chemical Process Engineering, [S. l.], v. 4, n. 2, p. 83–89, 2019. DOI: 10.33536/jcpe.v4i2.846. Disponível em: https://jurnal.fti.umi.ac.id/index.php/JCPE/article/view/846. Acesso em: 1 jul. 2025.