1. T. Sekine and Y. Hasegawa. “Solvent Extraction Chemistry. Fundamentals and Applications,” Marcel Dekker, New York (1977).
2. “Principles and Practices of Solvent Extraction,” J. Rydberg, C. Musikas, and G.R. Choppin, eds., Marcel Dekker, New York (1992).
3. R.D. Rogers, A.H. Bond, and C.B. Bauer, Metal ion separations in polyethylene glycol-based aqueous biphasic systems, Sep. Sci. Technol. 28:1091 (1993).
4. P.-A. Albertsson. “Partition of Cell Particles and Macromolecules,” 3rd ed., John Wiley & Sons, New York (1985).
5. “Methods in Enzymology. Aqueous Two-Phase Systems,” Vol. 228, H. Walter and G. Johansson, eds., Academic Press, Inc., San Diego, CA (1994).