1. Many good reviews exist in the literature, see for example A.H. Mueller, Phys. Rep. 73C, (1981), 239 and references therein,
2. C.T.C. Sachrajda in M.K. Gaillard and R. Stora eds, “Gauge Theories in High Energy Physics”, North-Holland, (1983).
3. S.J. Brodsky and G.R. Farrar, Phys. Rev. Lett., 31, (1973), 1153
4. S.J. Brodsky and G.R. Farrar, Phys. Rev., Dl1, (1975), 1309.
5. V.A. Matveev, R.M. Muradyan and A.V. Tavkheldize, Lett. Nuovo Cimento 7, (1973), 710.