1. H. Flaschka, Chemist Analyst44, 2 (1955).
2. S. Y. Shen and M. Kakaty, Mikrochim. Acta [Wien]1971, 96.
3. E. H. Swift and F. C. Anson, in C. N. Reily (Ed.): Advances in Analytical Chemistry and Instrumentation, Volume-I, New York: Interscience. 1960. p. 293.
4. A. Milczarska and S. Petri, Ann. acad. med. Lodz8, 157 (1966).
5. A. Claeys, H. Sion, A. Campe, and H. Thun, Bull. soc. chim. Belge70, 576 (1961).