GRB 130603B: WHT optical afterglow candidate. Levan, A. J. ; Tanvir, N. R. ; Wiersema, K. ; Hartoog, O. ; Kolle, K. ; Mendez, J. ; Kupfer, T. Abstract Publication: GRB Coordinates Network Pub Date: 2013 Bibcode: 2013GCN.14742....1L