1. S. Bartulucci et al., DESY Report 77 /59 (1977).
2. See C. Bemporad, repporteur talk, 1977 Hamburg Conference, p. 196.
3. See F. Laplanche, rapporteur talk, 1977 Hamburg Conference, p. 189.
4. E. Lohrmann, summary talk, 1977 Hamburg Conference, p. 641.
5. R. Anderson et al., Phys. Rev. Dl (1970) 27.