Predictions for single spin asymmetries in $\ell p^{\uparrow} → π X$ and $γ^* p^{\uparrow} → π X$ - Anselmino, M.; Boglione, M.; Hansson, J.; Murgia, F. (Springer, 2000)
http://dx.doi.org/10.1007/s100520000339
Keywords: U