GRB060923 - SDSS pre-burst observations. Cool, R. J. ; Eisenstein, D. J. ; Hogg, D. W. ; Blanton, M. R. ; Schlegel, D. J. ; Brinkmann, J. ; Lamb, D. Q. ; Schneider, D. P. ; vanden Berk, D. E. Abstract Publication: GRB Coordinates Network Pub Date: 2006 Bibcode: 2006GCN..5585....1C