1. R. F. Milton andW. A. Waters, Methods of Quantitative Micro-Analysis. London: Edward Arnold and Co. 1949, p. 20.
2. G. Kainz, Mikrochim. Acta [Wien]1953, 117.
3. T. S. Ma andA. A. Benedetti-Pichler, Analyt. Chemistry25, 999 (1953).
4. H. F. Arletter, Analyt. Chemistry, in press.
5. A. A. Benedetti-Pichler, Introduction to the Microtechnique of Inorganic Analysis. New York: J. Wiley and Sons, 1942, p. 197.