1. 1) CIE. Standardization of Luminance Distribution on Clear Skies. (1973)
2. 2) CIE. Spatial distribution of daylight-Overcast sky and clear sky. (1994)
3. 3) CIE. Natural daylight, Official recommendation, Compte Rendu. CIE 13th Session, Committee E-3.2, 1955. (1955) vol.II, p.part 3-2.
4. 4) GOTO K. Radiance distribution of clear sky and overcast sky. Proc. 4th Lux Pacifica, 1997. (1997) vol."E-46"-"E51",
5. 5) CIE. Guide to recommended practice of daylight measurement.