1. “Elements of Ion Exchange.”;Kunin,1960
2. (a) R. Kunin, private communication.
3. Dowex: Ion Exchange. Published by the Dow Chemical Co., 1958.
4. Pectin production from grapefruit peel;Beohner;Ind. Eng. Chem.,1949
5. S. J. Hussey, U.S. Bur. Mines Rept. Invest. No. 4374 (1949).