Effective $\Delta S=1$ weak chiral Lagrangian from the instanton-induced   chiral quark model
  We present the recent investigation of the $\Delta S = 1$ effective weak chiral Lagrangian within the framework of the instanton-induced chiral quark model. Starting from the effective four-quark operators, we derive the effective weak chiral action by integrating out the constituent quark fields. Employing the derivative expansion, we obtain the effective weak chiral Lagrangian to ${\cal O} (p^4)$ order with low energy constants. 
Mario Franz, Hyun-Chul Kim, and Klaus Goeke