1. W. Geist and S. Reucroft, Proc. of the Workshop on SPS Fixed Target Physics, CERN 83-02 Vol. II: 190 (1983);
2. J. Sacton, Proc. of the Workshop on SPS Fixed Target Physics, CERN 83-02 Vol.11: 222 (1983),
3. S. Reucroft, XXIV Int. Symposium on Multiparticle Dynamics, Lake Tahoe, California, preprint CERN-EP/83-155 (1983);
4. N.W. Reay, Proc. of the Int. Conference “Physics in Collision III7”, Como — Italy, Edit. Frontieres p.223 (1983). represented a good source of information in preparing this invited talk.
5. D. Aston et al., Phys. Lett. 100B: 91 (1981)