1. Anderson, B. B. (1964). J. clin. Path., 17, 14.
2. Bauer, H., and Heinrich, H. C. (1961). In Chemical Pathology of the Nervous System, edited by J. Folch-Pi, p. 120. Pergamon Press, Oxford.
3. Clausen, J., and Munkner, T. (1962). Acta path. microbiol. scand., 54, 129.
4. Gjertsen, F. A., and Schrumpf(1962). Nord. Med., 67, 162.
5. Grann, V., and Glass, G. B. J. (1961). J. Lab. clin. Med., 57, 562.