BeppoSAX discovery of the X-ray afterglow of GRB 971227 L. A. Antonelli, F. Fiore, L. Amati, M. Feroci, E. Costa, F. Frontera, G. Gandolfi, P. Giommi and L. Piro Astron. Astrophys. Suppl. Ser., 138 3 (1999) 435-436 Published online: 15 September 1999 DOI: 10.1051/aas:1999109