1. E. J. Weidmann andJ. C. Anderson, Thin Solid Films,7, 265 1971.
2. R. I. Dawood, A. H. Eid andKh. A. Mady, Egypt. J. Phys.3, 37, 1972.
3. A. H. Eid, E. A. Abou-Seif, N. E. Abdel-Aziz andS. Kishk, Proc. Phys. and Math. Soc. Egypt.
4. S. Tolansky, Introduction to Interferometry, Longmans Green Co., London, 157 (1955).
5. A. Goswami andR. H. Jog, Indian J. Pure and Appl. Phys.,6, 416, 1968.