1. Abbott, L. D., Jr., and Smith, J. D. (1949). J. biol. Chem., 179, 365.
2. Abelin, I., and Goldstein, M. (1955). Biochem. Z., 327, 72.
3. Aronow, L., and Howard, F. A. (1955). Fed. Proc., 14, 315.
4. Bergstrom, S., and Hansson, G. (1951). Acta physiol. scand., 22, 87.
5. Bone, A. D. (1953). J. med. Lab. Technol., 11, 212.