1. R. P. Feynman, Phys. Rev. Lett. 23:1415 (1969); and R. P. Feynman, “Photo-Hadron Interactions,” W. A. Benjamin, Reading, Mass., (1972).
2. J. D. Bjorken, Phys. Rev 179: 1547 (1969).
3. W. K. H. Panofsky, rapporteur’s talk, in “Proceedings of the Fourteenth International Conference on High Energy Physics, at Vienna, Austria,” CERN Scientific Information Service, Geneva, Switzerland, (1968) p. 23.
4. G. Miller, Ph. D thesis, SLAC Report No. 129 (1971); see also E. D. Bloom and F. J. Gilman, Phys. Rev. D4: 2901 (1971).
5. M. Breidenbach and J. Kuti, LNS-MIT Report No. 247 (1971); see also 0. Nachtmann, Nucl. Phys. B63: 237 (1973).