The muon anomalous magnetic moment in QED: three-loop electron and tau   contributions
  We present an analytic calculation of electron and tau O(alpha^3) loop effects on the muon anomalous magnetic moment. Computation of such three-loop diagrams with three mass scales is possible using asymptotic and eikonal expansions. An evaluation of a new type of eikonal integrals is presented in some detail. 
Andrzej Czarnecki and Maciej Skrzypek