Four-Fermion Interaction in the Low-Energy Approximation of Quantum   Chromodynamics
  A model with the four-fermion interaction is derived using the self-consistent field method in the low-energy limit of quantum chromodynamics. The resulting Lagrangian contains not only the trivial and chiral terms but also the interaction of the vector and pseudovector currents. 
S.V. Kutnii, P.I. Golod
hep-th