GRB 090531B: Swift/BAT spectral lag results. Ukwatta, T. N. ; Barthelmy, S. D. ; Cummings, J. R. ; Sakamoto, T. ; Stamatikos, M. ; Gehrels, N. Abstract Publication: GRB Coordinates Network Pub Date: 2009 Bibcode: 2009GCN..9475....1U