G/G Models and W_N strings
  We derive the BRST cohomology of the G/G topological model for the case of A^{(1)}_{N-1} . It is shown that at level k={p/q}-N the latter describes the (p,q) W_N minimal model coupled to $W_N$ gravity (plus some extra ``topological sectors"). 
O. Aharony, J. Sonnenschein and S. Yankielowicz