SDSS_QSOSchneider, D. P., Hall, P. B., Richards, G. T., Strauss, M. A., Vanden Berk, D. E. and 39 others (2007) The Sloan Digital Sky Survey Quasar Catalog. IV. Fifth Data Release, Astronomical Journal, 134, 102-117 http://adsabs.harvard.edu/abs/2007AJ....134..102S
York, D. G., Adelman, J., Anderson, J. E., Anderson, S. F., Annis, J., and 140 others (2000) The Sloan Digital Sky Survey: Technical Summary, Astronomical Journal, 120, 1579-1587 http://adsabs.harvard.edu/abs/2000AJ....120.1579Y