Some remarks on the epsilon-expansion of dimensionally regulated Feynman   diagrams
  Some problems related to construction of the epsilon-expansion of dimensionally regulated Feynman integrals are discussed. For certain classes of diagrams, an arbitrary term of the epsilon-expansion can be expressed in terms of log-sine integrals related to the polylogarithms. It is shown how the analytic continuation of these functions can be constructed in terms of the generalized Nielsen polylogarithms. 
A.I. Davydychev and M.Yu. Kalmykov