References

• Bloom J.S., Djorgovski S.G., Kulkarni S.R., Frail D.A., 1998, ApJL 507, 25
• Boella G., et al., 1997, A&AS 122, 299 NASA ADS
• Boettcher M., Dermer C.D.D., Crider A.W., Liang E.D., 1999, A&A 343, 111 NASA ADS
• Costa E., et al., 1997, Nat 387, 783 NASA ADS
• Costa E., 1999 (these proceedings)
• Djorgovski S.G., et al., 1999, ApJ (in press)
• Ghisellini G., et al., 1998, ApJ (submitted; see also these Proc.)
• Kulkarni S.R., et al., 1998, Nat 395, 663 NASA ADS
• Lazzati D., Ghisellini G., Campana S., 1999, MNRAS (in press; see also these Proc.)
• Mészáros P., Rees M.J., 1998, MNRAS 299, L10 NASA ADS
• Metzger M.R., et al., 1997, Nat 387, 878 NASA ADS
• Perna R., Loeb A., 1998, ApJ 501, 467 NASA ADS
• Piro L., Scarsi L., Butler R.C., 1995, in: X-Ray and EUV/FUV Spectroscopy and Polarimetry, Fineschi S. (ed.), SPIE 2517, p. 169-181
• Piro L., et al., 1998a, A&A 329, 906 NASA ADS
• Piro L., et al., 1998b, A&A 331, L41 NASA ADS
• Piro L., et al., 1999, ApJL 514, L73 NASA ADS
• van Paradijs, et al., 1997, Nat 386, 686 NASA ADS
• Vietri M., Stella L., 1998, ApJ 507, L45 NASA ADS
• Yoshida A., et al., 1999 (these proceedings)