1. Proc. Pavia Symposium on multi particle production 1973, p. 93.
2. Proc. Zakopane Symposium on multi particle production 1972, p. 314.
3. Proc. 1973 CERN-JINR School of Physics, Report CERN-73-12 (1973), p. 171.
4. Proc. Pavia Symposium on multi particle production 1973, p. 265.
5. XIII. Cracow School of Physics 1973.