1. Wilbrandt, W., and Rosenberg, T., Pharmacol. Rev., 13, 109 (1961).
2. Bowyer, F., Intern. Rev. Cytol., 6, 469 (1957).
3. Levine, M., and Stein, W. D., Biochim. Biophys. Acta, 127, 179 (1966).
4. LeFevre, P. G., Habich, K. I., Hess, H. S., and Hudson, M. R., Science, 143, 955 (1964).
5. Stein, W. D., in Structure and Activity of Enzymes, 133, edit. by Goodwin, T. W., Harris, J. I., and Hartley, B. S. (Academic Press, London, 1964).