1. Commission Internationale d’Eclairage (CIE). International Lighting Vocabulary. Bureau Central de la CIE, Paris, 1970.
2. Illuminating Engineers Society (IES). Lighting Handbook, fifth edition. Illuminating Engineering Society of North America, New York, 1972.
3. Henderson, S. T. Daylight and Its Spectrum. American Elsevier, New York, 1970.
4. Stair, R. Measurement of natural ultraviolet radiation: Historical and general introduction. In The Biologic Effects of Ultraviolet Radiation (with Emphasis on the Skin) (F. Urbach, Ed.). Pergamon Press, Oxford, 1969, pp. 377–391.
5. Buettner, K. The effects of natural sunlight on human skin. In The Biologic Effects of Ultraviolet Radiation (with Emphasis on the Skin) (F. Urbach, Ed). Pergamon Press, Oxford, 1969, pp. 237–251.