A new example of N=2 supersymmetric Landau-Ginzburg theories: the   two-ring case
  The new example of N=2 supersymmetric Landau-Ginzburg theories is considered when the critical values of the superpotential w(x) form the regular two-ring configuration. It is shown that at the deformation, which does not change the form of this configuration, the vacuum state metric satisfies the equation of non-Abelian 2 x 2 Toda system. 
A.M. Perelomov and S.-s. Roan