Axial Anomaly through Analytic Regularization
  In this work we consider the 2-point Green's functions in (1+1) dimensional quantum electrodynamics and show that the correct implementation of analytic regularization gives a gauge invariant result for the vaccum polarization amplitude and the correct coefficient for the axial anomaly. 
L. A. Manzoni, B. M. Pimentel and J. L. Tomazelli