1. Lemlich, E., ed., “Adsorptive Bubble Separation Technique”, (a) P. 3, (b) P. 36 (c) p. 244, Academic Press, New York (1972).
2. Schoen, H. M. ed., “New Chemical Engineering Separation Techniques”, Chapter 5, Interscience, New York, (1962).
3. Somasundaran, P., Am. Chem. Soc. Symp. on “Colloid and Surface Chemical Methods of Separation” 162nd Nat. Mtg., Washington, D.C. (1972).
4. Concentration by Ion Flotation