1. Airapetian, A., et al.: (2004).
arXiv:hep-ex/0408013
2. Alguard, M.J., et al.: Phys. Rev. Lett. 37, 1281 (1976)
3. Altarelli, G., Parisi, G.: Nucl. Phys. B 126, 298 (1977)
4. Anselmino, M., Gambino, P., Kalinowski, J.: Z. Phys. C 64, 267 (1994)
5. Artru, X.: In: Proceedings of the Fifth Workshop on High Energy Spin Physics, Protvino, Russia, p. 152 (1993)