One-loop results for three-gluon vertex in arbitrary gauge and dimension
  We review the calculation of one-loop contributions to the three-gluon vertex, for arbitrary (off-shell) external momenta, in arbitrary covariant gauge and in arbitrary space-time dimension. We discuss how one can get the results for all on-shell limits of interest directly from the general off-shell expression. 
A. I. Davydychev, P. Osland (Bergen), O. V. Tarasov (DESY-Zeuthen)