1. See, for example, John Ellis, SLAC-PUB-2121 (1978); W. Marciano and H. Pagels, Phys. Reports C36, 137 (1977).
2. O. W. Greenberg and C. A. Nelson, Phys. Reports C32, 69 (1977).
3. K. Gottfried, Proceedings of the 1977 International Symposium on Lepton and Photon Interactions at High Energies, Hamburg, Ed. F. Gutbrod (DESY, 1977), p. 667.
4. Asymptotic freedom: H. D. Politzer, Phys. Reports 14C, 129 (1974).
5. D. J. Gross and F. A. Wilczek, Phys. Rev. Lett. 30, 1343 (1973); H. D. Politzer, ibid., 1346 (1973).