Ungerer, Maria, Derik van der Westhuizen, Gerhard Lachmann, and Henning Krieg. “Separation of Tantalum and Niobium With Solvent Extraction”. Suid-Afrikaans Tydskrif vir Natuurwetenskap en Tegnologie / <i>South African Journal of Science and Technology</i&gt; 33, no. 1 (June 13, 2014): 2 bladsye. Accessed March 5, 2024. http://www.satnt.ac.za/index.php/satnt/article/view/473.