1. Handbook of Fundamentals;ASHRAE,1981
2. A modification of the ASHRAE clear sky irradiation model;Machler;ASHRAE Trans.,1985
3. Comparison of solar radiation sensors from various manufacturers;Flowers,1978
4. Calibration and testing of pyranometers;Andersson,1981
5. Spectral distribution of radiation from sun and sky;Hall;Trans. Illum. Eng. Soc. London,1954