QCD corrections up to order alpha_s^2 to polarized quark production in   e^+ e^- -annihilation
  The revised version contains two additional references i.e. [13], [14] w.r.t. to the original paper. Furthermore Eq. (33) in [11] at the end of the paragraph below (3.17) must be Eq. (33) in [10]. Misprints in the list of references are corrected. 
V. Ravindran and W.L. van Neerven