1. Weinstein, Chemistry in Medicine. 1928. p. 68.
2. Pearl, R., The Rate of Living. London. 1928.
3. Handschin, E., 1932: Pamphl. Coun. Sci. Industr. Res. Australia
31.
4. Breitenbrecher, J. K., 1926: Trans. R. Soc. Canada Sect.
V, 269.
5. Tenenbaum, E., 1933: Biol. Zbl.
53, 308.