1. M. M. Block, R. Gessaroli, J. Kopelman, S. Ratti, M. Schneeberger, L. Grimellini, T. Kikuchi, L. Lendinara, L. Monari, W. Becker andE. Harth:Proceedings of the International Conference on Hyperfragments, 1963, CERN-(64-1) (1964), p. 63.
2. J. Sacton:Proceedings of the International Conference on Hyperfragments, St. Cergue, 1963, CERN-(64-1) (1964), p. 53.
3. B. Bhowmik, D. P. Goyal andN. K. Yamdagni:Phys. Lett.,3, 13 (1962).
4. J. P. Lagnaux: Bruxelles University Report No. 12 (1964).
5. J. Cuevas, J. Diaz, D. M. Harmsen, W. Just, E. Lohrmann, L. Schink, H. Spitzer andM. W. Teucher:Nucl. Phys.,1 B, 411 (1967).