1. J.S. Preston, A.C. du Preez, The solvent extraction of cobalt, nickel, zinc, copper, calcium, magnesium, and the rare-earth metals by organophosphorous acids, Report M378, Mintek, South Africa, 1988
2. Permeation of neodymium and praseodymium through supported liquid membranes containing di-(2-ethylhexyl)phosphoric acid as a carrier;Moreno;J. Membr. Sci.,1993
3. J. Doležal, C. Moreno, A. Hrdlička, M. Valiente, Unpublished results
4. The solvent extraction of europium(II) by some organophosphorus and carboxylic acids;Preston;Solvent Extr. Ion Exch.,1991
5. Z. Kolarik, Interactions of acidic organophosphorus extractants in the organic phase, in: Y. Markus (Ed.), Solvent Extraction Reviews, vol. 1, Marcel Dekker, New York, 1971