1. Abdel-Wahab, E. M., and Laurence, D. J. R. (1955). Biochem. J., 60, xxxv.
2. Cremer, H. D., and Tiselius, A. (1950). Biochem. Z., 320, 273.
3. Dangerfield, W. G., and Smith, E. B. (1955). J. clin. Path., 8, 132.
4. Discombe, G., Jones, R. F., and Winstanley, D. P. (1954). Ibid., 7, 106.
5. Franglen, G. (1956). In Ciba Foundation Symposium on Paper