Single-spin asymmetries for small-angle pion production in high-energy hadron collisions A. Ahmedov, I.V. Akushevich, E.A. Kuraev and P.G. RatcliffeEur. Phys. J. C, 11 4 (1999) 703-708DOI: https://doi.org/epjc/v11/p703(epjc0210)