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		| Paper: | Representations of World Coordinates in FITS |  
		| Volume: | 216, Astronomical Data Analysis Software and Systems IX |  
		| Page: | 571 |  
		| Authors: | Calabretta, M.; Greisen, E. W. |  
		| Abstract: | The original FITS papers provided a simplified, non-specific method for describing the physical coordinate values of image pixels. In the intervening 20 years, there have been a number of implementations of coordinates in astronomical software packages and several attempts to obtain agreement on their representation in FITS. A general consensus on the important details has been obtained and is described here. |  
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