Limits of colour charge interaction in the instanton liquid
  The effect of external colour field impact on the instanton liquid is studied. In the course of this study the corresponding effective Lagrangians are derived for both regimes of weak and strong external field and in long wave-length approximation. The example of Euclidean colour point-like source is analyzed in detail and the feedback of field on the instanton liquid is estimated as a function of source intensity. 
S.V. Molodtsov, G.M. Zinovjev