Quark momentum distributions fromep collisions: strategies and prospects

We present the results of a comprehensive investigation of possibilities to extract structure functions and momentum distributions of individual quark flavours from cross-section measurements atep colliders. Approximate determinations based on single cross-sections are examined and compared with an exact unfolding procedure which, however, requires the combination of neutral and charged current data for both electron and positron beams. Using Monte Carlo methods we evaluate the precision that can be expected from the forthcoming HERA experiments in measuring the shape in Bjorken-x of structure functions and quark distributions.