1. Photometry;Walsh,1953
2. “International Lighting Vocabulary,” CIE 17.4/IEC 50(845) (1987).
3. “International Vocabulary of Basic and General Terms in Metrology,” BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, and OIML (1994).
4. “Quantities and Units: ISO Standards Handbook”, IEC, Switzerland, 1993.
5. CIE Compte Rendu, p. 67, (1924).