K0-K0bar Mixing with Wilson Fermions without Subtractions
  By using suitable Ward identities, we show that it is possible to compute K0-K0bar mixing without subtracting the terms generated by explicit chiral symmetry breaking present in Wilson-like lattice actions. The accuracy in the determination of the amplitudes is of O(a), which is the best one attainable in the absence of improvement. 
D.Becirevic, Ph.Boucaud, V.Gimenez, V.Lubicz, G. Martinelli,   J.Micheli, M.Papinutto