1. R. K. Luneberg, Mathematical theory of optics, Brown Univ. Lecture Notes, (1944), Univ. of California Press, Berkley, (1964).
2. G. Lansraux, Rev. d’optique, 26, 24 (1947).
3. G. Lansraux, Thesis, Paris University, (1953).
4. G. Lansraux and G. Boivin, Can. J. Phy., 39, 158 (1961).
5. P. Jacquinot and Mme. B. Roizen-bossier, in Progress in Optics, Vol. III, Ed. E. Wolf, North-Holland Publishing Co., Amsterdam, (1964).