The puzzling case of GRB 990123: multiwavelength afterglow study E. Maiorano, N. Masetti, E. Palazzi, F. Frontera, P. Grandi, E. Pian, L. Amati, L. Nicastro, P. Soffitta, C. Guidorzi et al. (11 more) A&A, 438 3 (2005) 821-827 Published online: 18 July 2005 DOI: 10.1051/0004-6361:20042534