1. M. Bouger, Traité d’Optique sur la Gradation de la Lumière, Académie Royale des Sciences, A. Paris, MDCCLX (1760) - see also: M. Bouger, Optical tractât on grading light, with commentaries by A.A. Gershun, translated from French to Russian by N.A. Tosltoy and P.P. Pheophilov under editorship of A.A. Gershun, published by Academy of Sciences of USSR, Leningrad (1950)
2. J.H. Lambert, Photometria sive de mensura et gradibus luminus, colorum et umbrae (Klett, Augsburg, 1760)
3. A.J. Fresnel, Oevres Complètes, vol. 10 (Paris, 1866), pp. 640–648
4. C. Fabry, Introduction Générale à la Photométrie, Edition de la revue d’optique theoretique et instrumentale, Paris (1927)
5. A.A. Gersun, Svetovoe Pole (GTTI, Moscow, 1936) (The Light Field, translated by P. Moon and G. Timoshenko, J. Math. Phys., 1939, Vol. 19, p. 51)