GRB030328: r upper limit after 6 hours by MASTER. Lipunov, V. ; Krylov, A. ; Kornilov, V. ; Borisov, G. ; Belinski, A. ; Chilingarian, I. ; Kuvshinov, D. ; Kuznetsov, M. ; Potanin, S. ; Vitrischak, V. Abstract Publication: GRB Coordinates Network Pub Date: 2003 Bibcode: 2003GCN..2103....1L