1. W.B. Atwood et al., Proc. XVII International Conference on High Energy Physics, London, p.IV-60 (1974).
2. K.W. Chen, Proc. International Conference on High Energy Physics, Palermo (1975) to be published.
3. R.P. Feynman, “Photon-Hadron-Interaction”, W.A. Benjamin, New York (1972).
4. J.D. Bjorken and E.A. Paschos, Phys. Rev. 185, 1975 (1969).
5. R.E. Taylor, Proc. international Symposium on Lepton and Photon Interactions at High Energies, Stanford (1975), to be published.