1. Middleton Instruments Division of Synchrotac Instruments, Victoria, Australia.
2. Technical Measurements Inc., La Canada, California.
3. American Society for Testing and Materials Standard E816-81.
4. An investigation of the Linke-Feussner pyrheliometer temperature coefficient;Pascoe;Solar Energy,1980
5. Meteorological aspects of the utilization of solar radiation as an energy source;World Meteorological Organization publication No. 557,1981