A strategy for the off-shell analysis of collinear singularities in   Feynman diagrams
  In my PHD thesis I present a method for the off-shell singularity analysis of Feynman amplitudes based on the Speer sector decomposition of the Schwinger parametric integrals combined with the Mellin-Barnes tranform. I apply the method to one-loop corrections to Deep Inelastic Scattering. 
Alessandra Repetto
hep-th