1. Feick, H., and H. M. Anderson: Ind. Eng. Chem. 44, 404 (1952).
2. Kutscher, F., u. H. Steudel: Z. Physiol. Chem. 39, 474 (1903).
3. Rubin, B., and H. R. Lehman: U.S. At. Energy Comm. UCRL-718 (1950).
4. Sanderson, W. W., and C. B. Ceresia: J. water pollution control federation 37, 1176 (1965).
5. Sherwood, T. K.: Absorption and extraction. 1st Edit. New York: McGrawHill 1937.