1. Berge., M.J. and Seltzer, S.M., Nucl. Instr. Meth., 104, 317, 1972.
2. Beuermann, K.P., Proc. 8th ESLAB-Symp., Frascati, 1974.
3. Bignami, G.F. and Fichtel, C.E., Astrophys. J., 189, L65, 1974.
4. Brandt, J.C., Stecher, T.P., Crawford, D.L. and Maran, S.P., Astrophys. J., 163, L99, 1971.
5. Caravane Collaboration of Cos-B, Proc. 8th ESLAB-Symp., Frascati, 1974.