1. Gringorten, I. I., andA. J. Kantor: Handbook of Geophysics and Space Environments, ed. Shea L. Walley, p. 3–17. New York: McGraw-Hill, 1965.
2. Outcalt, S. I.: Water Resources Research,5, 1377 (1969).
3. Allen, C. W.: Astrophysical Quantities. 2nd edition, p. 170, London: Athlone Press, 1963.
4. Duncombe, J. S.: U. S. Naval Observatory Circular, no. 125 (1969).
5. Moon, P.: Proposed Standard Solar Radiation Curves for Engineering Use. J. Frankling Institute,230, p. 583 (1940).