1. J.-L. Atteia, C. Barat, E. Jourdain, et al., Nature 351, 296 (1991).
2. C. Barat, F. Cotin, M. Niel, et al., AIP Conf. Proc. 170, 395 (1998).
3. J.-P. Dezalay, C. Barat, R. Talon, et al., in Gamma-Ray Bursts, Ed. by W. S. Paciesas and C. J. Fishman (American Inst. of Physics, New York, 1992), vol. 304.
4. J.-P. Dezalay, J.-L. Atteia, C. Barat, et al., Astron. Astrophys. 286, 103 (1994).
5. J. C. Higdon and M. Schmidt, Astrophys. J. 355, 13 (1990).