The structure functions of longitudinal virtual photon at low   virtualities
  The structure functions of longitudinal virtual photon at low virtualities are calculated in the framework of chiral pertubation theory(ChPT) in the zero and first order of ChPT. It is assumed that the virtuality of target longitudinal photon is much less than the virtuality of the hard projectile photon and both are less than the characteristic ChPT scale. 
B.L. Ioffe and I.A. Shushpanov (Institute for Theoretical and   Experimental Physics, Moscow, Russia)