Azimuthal Spin Asymmetries in Semi-Inclusive Production from   Positron-Proton Scattering
  The recent measurements of azimuthal single spin asymmetries by the HERMES collaboration at DESY may shed some light on presently unknown fragmentation and distribution functions. We present a study of such functions and give some estimates of weighted integrals directly related to those measurements. 
M. Boglione and P.J. Mulders