1. Holt, S. S., Proc. Cospar Symp. Fast Transients X and gamma ray Astronomy, Astrophys. Space Sci., (in the press).
2. Gursky, H., et al., IAU Circ. no. 2778 (1975).
3. Rothschild, R. E., Boldt, E. A., Holt, S. S., and Serlemitsos, P. J., Bull. Am. Phys. Soc., 20, 604 (1975).
4. Tananbaum, H., Gursky, H., Kellogg, E., Giacconi, R., and Jones, C., Astrophys. J. Lett., 177, L5 (1972).
5. Rothschild, R. E., Boldt, E. A., Holt, S. S., and Serlemitsos, P. J., Astrophys. J. Lett., 180, L13 (1974).