1. A. Mueller (ed.),Perturbative Quantum Chromodynamics, World Scientific, Singapore (1987).
2. S. M. Troshin and N. E. Tyurin,Int. J. Mod. Phys. A,5, 2689 (1990).
3. J. D. Bjorken, in:Proceedings of 3rd International Symposium on Electron and Photon Interactions, Stanford, California (1967);
4. R. P. Feynman,Phys. Rev. Lett.,23, 1415 (1969).
5. A. D. Krisch, Plenary Lecture Given at the Ninth International Symposium on High Energy Spin Physics, Bonn, September (1990).