Valence and sea contributions to the nucleon spin O.Yu. Shevchenko, R.R. Akhunzyanov and V.Yu. Lavrentyev Eur. Phys. J. C, 71 8 (2011) 1713 Published online: 02 August 2011 DOI: 10.1140/epjc/s10052-011-1713-3