1. A. J. G. Hey:Daresbury Lecture Note Series, No. 13,Polarization effects in electronproton scattering form factors, scaling, quarks and SU 6w, where one not only finds a thorough discussion of the problem, but also a list of earlier papers on the subject (in footnote (31)).
2. E.g.:G. R. Farrar:Nucl. Phys.,77 B, 429 (1974);V. Barger andR. J. N. Phillips:Nucl. Phys.,73 B, 269 (1974).
3. The notation followsF. J. Gilman: inProceedings of the XVII International Conference on High-Energy Physics, edited byJ. R. Smith (London, 1974).
4. See, for example,J. D. Bjorken: inCurrent Induced Reactions, Lecture Notes in Physics 56, edited byJ. G. Körner, G. Kramer andD. Schildknecht.
5. A good introduction into this field can be found in ref. (1), chapter 4, where some of the original papers on the subject are also listed.