References
- American National Standard Practice for Industrial Lighting, A 11.1—1965 (Reaffirmed 1970). American National Standards Institute, New York and Illuminating Engineering, Vol. 60, March 1965, p. 103.
- American National Standard Practice for Office Lighting, A 132.1–1966. American National Standards Institute, New York and Illuminating Engineering, Vol. 55, June 1960, p. 313.
- IES Lighting Handbook, Illuminating Engineering Society, 345 East 47th Street, New York, N. Y. 10017.