Probing a nucleon spin structure at TESLA by the real polarized gamma beam S. Alekhin, V. Borodulin, A. Çelikel, M. Kantar and S. Sultansoy Eur. Phys. J. C, 11 2 (1999) 301-307 Published online: 14 October 1999 DOI: 10.1007/s100529900184