1. S. P. K. Tavernier, Rep. Prog. Phys. 50 (1987) 1439.
2. S. D. Holmes, W. Lee and J. E. Wiss, Ann. Rev. Nucl. Part. Sci. 35 (1985) 397.
3. C. Albajar,Cern preprint, CERN-EP 87/190 (October 1987).
4. J. C. Collins, D. E. Soper and G. Sterman, Nucl. Phys. B263 (1986) 37.
5. S. J. Brodsky, J. C. Collins, S.D. Ellis, J. F. Gunion and A. H. Mueller, in Proc. 1984 Summer Study on the Design and Utilization of the Superconducting Super Collider, R. Donaldson and J. Morfin, (eds.), Fermilab, Batavia, Illinois, 1984, p. 227.