On the Resummation of $\alpha \ln^2 x$ Terms for Non-Singlet Structure   Functions in QED and QCD
  The resummation of $O(\alpha^{l+1} \ln^{2l} x)$ terms in the evolution kernels of non--singlet combinations of structure functions is investigated for both QED abd QCD. Numerical results are presented for unpolarized and polarized structure functions. 
J. Bl\"umlein and A. Vogt