1. N. V. Sidgwick,The Chemical Elements and Their Compounds, Vol 1, Clarendon Press, Oxford, 1950.
2. M. Dub,Organometallic Compounds, Vol. II, 2nd Ed. (Last Supplement), Springer, Berlin, Heidelberg, New York, 1973, p. 901.
3. D. Colaitia, M. Lesbre,Bull. Soc. Chim. France 1952, 1069.
4. Y. A. Gawargious,M.Sc. Thesis, Birmingham University, England, 1961.
5. Y. A. Gawargious, A. M. G. Macdonald,Anal. Chim. Acta 1962,27, 119.