1. Vitamin A of butter;Morton;Biochem. J.,1930
2. Vitamin A and Carotin Notes on the conversion of carotin to vitamin A in the cow;Moore;Biochem. J.,1932
3. Davis, H. P., and Hathaway, I. L. The vitamin A content of milk of Holstein, Ayrshire, Jersey and Guernsey cows. Nebraska Agric. Exp. Sta. Bulletin No. 54. February, 1931.
4. Hathaway, I. L., and Davis, H. P. The vitamin A content of skimmilk, standardized milk and cream from different breeds of cows. Nebr. Agric. Exp. Sta. Bulletin No. 69. 1933.
5. The vitamin A activity of butter produced by Guernsey and Ayrshire cows;Wilbur;Jour. Dairy Sci.,1933