.. _wcslib: http://www.atnf.csiro.au/~mcalabre/WCS/
.. _pyfits: http://www.stsci.edu/resources/software_hardware/pyfits
.. _Paper IV: http://www.atnf.csiro.au/people/mcalabre/WCS/index.html
.. _SIP: http://ssc.spitzer.caltech.edu/postbcd/doc/shupeADASS.pdf
.. _ds9: http://hea-www.harvard.edu/RD/ds9/

