The Refined Elliptic Genus and Coulomb Gas Formulations of $N=2$   Superconformal Coset Models
  We describe, in some detail, a number of different Coulomb gas formulations of $N=2$ superconformal coset models. We also give the mappings between these formulations. The ultimate purpose of this is to show how the Landau-Ginzburg structure of these models can be used to extract the $W$-generators, and to show how the computation of the elliptic genus can be refined so as to extract very detailed information about the characters of component parts of the model. 
D. Nemeschansky and N. P. Warner