Kabangu, M. J. & Crouse, P. L.: Separation of niobium and tantalum from Mozambican tantalite by ammonium bifluoride digestion and octanol solvent extraction. Hydrometallurgy, 2012, s. 151–155. Artikkelin verkkoversio (pdf). Viitattu 16.2.2023. (englanniksi) (Arkistoitu – Internet Archive)
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Kabangu, M. J. & Crouse, P. L.: Separation of niobium and tantalum from Mozambican tantalite by ammonium bifluoride digestion and octanol solvent extraction. Hydrometallurgy, 2012, s. 151–155. Artikkelin verkkoversio (pdf). Viitattu 16.2.2023. (englanniksi) (Arkistoitu – Internet Archive)