1. Abedelrahman, M.A., S.A.M. Said, and A.N. Shuaib (1988), Comparison between atmospheric turbidity coefficients or desert and temperate climates, Solar Energy, 40(3): 219–225.
2. El-Hussainy, F.M. (1989), A study of atmospheric turbidity parameters over Cairo, ASHE, Cairo/Egypt, March 19–22, Vol.1, No. 6, pp 53–63.
3. Hanel, G. (1971), New results concerning the dependence of visibility on relative humidity and their significance in a model for visibility forecast. Beitrage zur Physik der Atmosphare. 44: 137–167.
4. Kasten, F. (1980), A simple parameterization of the pyrheliometric formula for determining the Linke turbidity factor, Meteorol. Rdsch., 33: 124–127 (1980).
5. Kasten, F. (1988), Elimination of the virtual diurnal variation of the Linke turbidity factor, Meteorol. Rdsch. 41: 93–94.