1. 5) Sugiura & Benedict, Journ. of biolog. chem. Vol. 55. 1923.
2. 8) Osborne & Mendel, Journ. of biolog. chem., 13, 1912.
3. 12) Funk & Mc Collum, Journ. of biolog. chem., 23, 1915.
4. 13) Funk & Dubin, Science, 52. 1920.
5. 14) Mori S., Amer. Journ. of hyg., Baltimore, 3. 1920.