Azimuthal Asymmetries in Inclusive Single Pion Electroproduction
  The leading and sub-leading order results for pion electroproduction in polarized and unpolarized semi-inclusive deep-inelastic scattering, are considered putting emphasis on transverse momentum dependent effects appearing in azimuthal asymmetries. In particular the spin-dependent (single, double) and spin-independent asymmetries of the distributions in the azimuthal angle of the pion related to the lepton scattering plane are discussed. 
K.A. Oganessyan