1. Crundwell, F., Moats, M., Ramachandran, V., Robinson, T. & Davenport, W. G. Extractive metallurgy of nickel, cobalt and platinum group metals. (Elsevier, Oxford, UK, 2011).
2. Cox, M. Solvent extraction in hydrometallurgy in “Solvent extraction principles and practices”. (eds Rydberg, J., Cox, M., Musikas, C. & Choppin, G. R.) Ch. 11, pp 455–505 (Marcel Dekker, 2004).
3. Matthey, Johnson Summary of Platinum Supply & Demand in 2017. PGM Market Reports February 2018, Johnson Matthey (2018).
4. Nuss, P. & Eckelman, M. Life cycle assessment of metals: A scientific synthesis. PLoS One 9, e101298 (2014).
5. Fornalczyk, A. Industrial catalysts as a source of valuable metals. J. Achie. Mat. Manuf. Eng. 55, 864–869 (2012).