1. ARNOLD, A., and ELVEHJEM, C. A. (1938). J. Nutr., 15, 403.
2. BARLETTA, V. (1932). Rass. ital. Ottal., 1, 210.
3. BERRY, C., NEUMANN, C., and HINSEY, J. C. (1945). J. Neurophysiol., 8, 315.
4. The Physiological Basis of Medical Practice;BEST, C.H.; TAYLOR, N.B.,1950
5. The Biological Standardisation of the vitamins;COWARD, K.H.,1947