1. H.M.N.H. Irving , Solvent Extraction, ed. D. Dyrssen , J.O. Lilienzin and J. Rydberg , North-Holland Press , Amsterdam , 1967 , pg. 91 .
2. Y. Marcus and A. S. Kertes , Ion Exchange and Solvent Extraction of Metal Complexes, John Wiley & Sons , New York , 1969 .
3. Studies of the Synergistic Effect