1. Chang, Tsing-Lien: Acta Chim. Sinica 22, 234 (1956).
2. Eriksen, K. F.: Biochem. J. 30, 264 (1936).
3. Hallaba, E., and M. S. Hamza: Isotopenpraxis 2, 458 to 461 (1966); cf. Z. Anal. Chem. 231, 441 (1967).
4. Isotopic water analysis, sec. Edit. AEC-tr-4136 1960.
5. Keston, A. S.: J. Biol. Chem. 122, 227 (1937).