Alguacil, F. J. “Solvent Extraction With DP-8R/LIX 860 Mixtures for the Selective Separation of Cobalt and Nickel”. Revista De Metalurgia, vol. 38, no. 3, June 2002, pp. 205-9, doi:10.3989/revmetalm.2002.v38.i3.402.