1. International Bureau of Weights and Measures (1960) The international system of units (Sr), 11th General Conference on Weights and Measures, BIPM.
2. International Bureau of Weights and Measures (1989) The international temperature scale (EIT-90),78th Session of International Committee of Weights and Measures, 57, BIPM.
3. International Electrotechnical Commission (1987), Electrotechnical vocabulary. Chap. 845: Lighting,CEI/IEC 50(845).
4. International Electrotechnical Commission (1996) Electrotechnical vocabulary. Chap. 111: Physics and Chemistry,CEI/IEC 50(111), 2nd edn.
5. International Organization for Standardization (1992) 31.0: Quantities and units. Part 0: General principles, 31.2: Part 4: Heat, Part 6: Light and related electromagnetic radiations,ISO 31(0), 3rd edn.