1. W.J. Rankin, J.S.J. Van Deventer: J. S. Afr. Inst. Min. Metall., 1980, vol. 80, pp. 239–47
2. W.J. Rankin, J.R. Wynnyckyj: Metall. Mater. Trans. B, 1997, vol. 28B, pp. 307–19
3. R.H. Eric, E. Bucuru: Miner. Eng., 1992, vol. 5, pp. 795–815
4. M.I. Gasik: Manganese, Metallurgiya, Moscow, 1992 (in Russian)
5. W.D. Grimsley, J.B. See, R.P. King: J. S. Afr. Inst. Min. Metall., 1977, vol. 10, pp. 51–62