1. Balint, P., and Bilint, M. Britton, C. J. C. (1945).
2. Middlesex Hosp;Balint, P.; Bilint, M.Britton; C, C.J.;Biochem. Z,1942
3. Cohen, P. P., Higgins, G., apd Thompson, F. O'Brien, J. R. P., L. (1947). J. Stewart, A., Lab. clin. Med., and Witts, L. J.
4. Brit. med. J., 1, 211.
5. Principles of Medical Statistics.;Hill, A.Bradford,1946