1. IUPAC-IUB Commission on Biochemical Nomenclature, Biochim. Biophys. Acta 107, 1 (1965).
2. T. Moore, Vitamin A (Elsevier, Amsterdam 1957).
3. G.A.J. Pitt, Proc. Nutr. Soc. 24, 153 (1965).
4. IUNS Committee on Nomenclature, Nutr. Abstr. Rev. 40, 395 (1970).
5. U. Schwieter and O. Isler, in The Vitamins, 2nd Ed., Vol. 1, ed. by W.H. Sebrell and R.S. Harris (Academic Press, New York 1967), p. 5.