1. Bevis, D. C. A. (1950) Lancet, ii, 443.
2. Cantarow, A., Stuckert, H., Davis, R. C. (1933) Surg. Gynec. Obstet. 57, 63.
3. Diamond, L. K., Vaughan, V. C., Allen, F. H. jun. (1950) Pediatrics, 6, 630.
4. Flexner, L. B., Gellhorn, A. (1942) Amer. J. Physiol. 136, 757.
5. King, E. J. (1951) Microanalysis in Medical Biochemistry. 2nd ed., London.