1. Simon, W., Rev. Sci. Instrum., 36, 1654 (1965).
2. McLachlan, jun., D., Sci. Res., 3, 65 (1968).
3. Maréchal, A., and Françon, M., Diffraction, Structure des Images (Revue d'Optique, Paris, 1960).
4. Stroke, G. W., An Introduction to Coherent Optics and Holographys, second ed. (Academic Press, New York and London, 1969).
5. Gabor, D., IBM J. Res. Develop., 14, 509 (1970).