1. I. J. Holcomb, S. A. Fusari, in:Analytical Profiles of Drug Substances, Vol. 3 (K. Florey, ed), Academic Press, Orlando, 1974, p. 173.
2. USP XVIII, United States Pharmacopoeial Convention, Rockville, MD, 1979, p. 2071.
3. T. Kashima,Chem. Pharm. Bull. 1958,6, 229.
4. H. Ellert, E. Sell,Farm. Pol. 1965,21, 167.
5. W. A. Dill, A. J. Glazko,J. Biol. Chem. 1949,179, 395.