GRB020331: third epoch and revised second epoch optical. Dullighan, A. ; Monnelly, G. ; Butler, N. ; Vanderspek, R. ; Ricker, G. ; Wang, Z. ; Challis, P. ; Kirshner, R. Abstract Publication: GRB Coordinates Network Pub Date: 2002 Bibcode: 2002GCN..1382....1D