Renormalization of non-locally regularized BRST-anti-BRST theories
  An extension of the non-local regularization scheme is formulated in the Sp(2) symmetric Lagrangian BRST quantization framework. It generates a systematic treatment of the anomalous quantum master equations and allows to substract the divergences as well as to calculate genuine higher loop BRST and anti-BRST anomalies. 
V. Calian, G. Stoenescu