1. Skeggs, L.T. (1957), Amer. J. Clin. Pathol., 28, 311.
2. Aris, R. (1956),Proc. Roy. Soc. A, 235,67.
3. Sutter, A., Gardanier, S.A. and Spooner, G.H. (1970), Amer. J. Clin. Pathol., 54,341.
4. Snyder, L.R. and Adler, HJ. (1916),And. Chem., 48,1017.
5. Snyder, L.R. (1976), Advances in Automated Analysis 7th Technicon International Congress. Vol. 1, Technicon Instrument Corp., Tarrytown, New York, p. 76.