1. Bouguer P. Traité d´Optique sur la gradation de la lumiére. Paris: 1760, Latin translation by Richtenburg J. Bougeri Optice de Diversis Luminis Gradibus Dimetiendis. Vienna-Prague, 1762, Russian translation by Tolstoy NA, Feofilova PP. Opticheskiy traktat o gradaciyi sveta, edited and commented by Gershun AA. Moscow: Publ. Acad. Sci. USSR; 1950, English translation by Knowles Middleton WE. Pierre Bouguer׳s optical treatise on the gradation of light. Toronto: University of Toronto Press; 1961.
2. Lambert JH. Photometria sive de mensura et gradibus luminis, colorum et umbrae. Augsburg: 1760. German translation by Anding E. Lamberts Fotometrie. Leipzig: Klett Publ.; 1892. English translation and notes by DiLaura DL. Photometry, or on the measure and gradation of light, colors and shade. New York: Publ. IESNA; 2001.
3. Über die Verteilung des Lichtes in der Atmosphäre;Schramm;Schrif Nat Vereins Schl Holst,1901
4. Flächenhelligkeit des Himmels und Beleuchtungsstärke in Räumen;Kähler;Meteorol Zeitschrift,1908
5. The photic field;Moon,1981