L. A. Corathers, “US Geological Survey (USGS) Minerals Yearbook: Manganese-2005,” 2007. http://minerals.usgs.gov
 W. Zhang and C. Y. Cheng, “Manganese Metallurgy Review: Part I: Leaching of Ores/Secondary Materials and Recovery of Electrolytic/Chemical Manganese Dioxide,” Hydrometallurgy, Vol. 89, No. 3-4, 2007, pp. 137-159. doi:10.1016/j.hydromet.2007.08.010
 N. Mulaudzi and T. Mahlangu, “Oxidative Precipitation of Mn(II) from Cobalt Leach Solutions Using Dilute SO2/ Air Gas Mixture,” The Journal of Southern African Institute of Mining and Metallurgy, Vol. 109, 2009, pp. 375381.
 J. Van Rooyen, S. Archer and M. Fox, “Manganese Removal from Cobalt Solutions with Dilute Sulphur Dioxide Gas Mixtures,” The Fourth Southern African Conference on Base Metals, The Southern Africa Institute of Mining and Metallurgy, 2009, pp. 365-376.
 V. Menard and G. Demopuolos, “Gas Transfer Kinetics and Redox Potential Considerations in Oxidative Precipitation of Manganese from an Industrial Zinc Sulphate Soltion with SO2/O2,” Hydrometallurgy, Vol. 89, No. 3-4, 2007, pp. 357-368. doi:10.1016/j.hydromet.2007.03.014
 T. Sato and T. Nakamura, “Solvent Extraction of Divalent Metals from Sulfuric Acid Solutions by Dialkylphosphoric Acid,” Journal of the Mining and Metallurgical Institute Japan, Vol. 101, No. 1167, 1985, pp. 309-312.
 D. Mohapatra, K. Hong-In, C. W. Nam and K. H. Park, “Liquid-Liquid Extraction of Aluminium(III) from Mixed Sulphate Solutions Using Sodium Salts of Cyanex 272 and D2EHPA,” Separation and Purification Technology, Vol. 56, No. 3, 2007, pp. 311-318. doi:10.1016/j.seppur.2007.02.017
 X. P. Huo, W. Qin, X. W. Sun and Y. Y. Dai, “Recovery of Chromium (III) by Solvent Extraction with D2EHPA,” Journal of Chemical Engineering of Chinese Universities, Vol. 21, No. 5, 2007, pp. 849-852.
 Z. G. Arroyo, M. Stambouli, D. Pareau, A. Buch, G. Durand and M. A. Rodriguez, “Thiosubstituted Organophosphorus Acids as Selective Extractants for Ag(I) from Acidic Thiourea Solutions,” Solvent Extraction and Ion Exchange, Vol. 26, No. 2, 2008, pp. 128-144. doi:10.1080/07366290801904855
 M. R. Hossain, S. Nash, G. Rose and S. Alam, “Cobalt Loaded D2EHPA for Selective Separation of Manganese from Cobalt Electrolyte Solution,” Hydrometallurgy, Vol. 107, No. 3-4, 2011, pp. 137-140. doi:10.1016/j.hydromet.2011.02.011
 S. Agatzini-Leonardou, P. E. Tsakiridis, P. Oustadakis, T. Karidakis and A. Katsiapi, “Hydrometallurgical Process for the Separation And Recovery of Nickel from Sulphate Heap Leach Liquor of Nickeliferrous Laterite Ores,” Minerals Engineering, Vol. 22, No. 14, 2009, pp. 1181-1192. doi:10.1016/j.mineng.2009.06.006
 S. ur Rehman, G. Akhtar, M. A. Chaudry, N. B. Najeebullah and N. Ali, “Mn (VII) Ions Transport by Triethanolamine Cyclohexanone Based Supported Liquid Membrane and Recovery of Mn (II) Ions from Discharged Zinc Carbon Dry Battery Cell,” Journal of Membrane Science, Vol. 366, No. 1-2, 2011, pp. 125-131. doi:10.1016/j.memsci.2010.09.049
 C. Y. Cheng, G. Boddy, W. Zhang, M. Godfrey, D. J. Robinson, Y. Pranolo, Z. Zhu and W. Wang, “Recovery of Nickel and Cobalt from Laterite Leach Solutions Using Direct Solvent Extraction: Part 1-Selection of a Synergistic SX System,” Hydrometallurgy, Vol. 104, No. 2, 2010, pp. 45-52. doi:10.1016/j.hydromet.2010.04.009
 R. K. Biswas, M. A. Habib and M. G. K. Mondal, “Kinetics and Mechanism of Stripping of Mn(II)-D2EHPA Complex by Sulfuric Acid Solution,” Hydrometallurgy, Vol. 80, No. 3, 2005, pp. 186-195. doi:10.1016/j.hydromet.2005.06.013