A BRST Operator for non-critical W-Strings
  We construct the BRST operator for non-critical $W_3$-strings and discuss the tachyon-like spectrum. For $N$-punctured spheres with $N \leq 5$ we briefly describe a formal definition of the integral over $W_3$-moduli space. 
M. Bershadsky, W. Lerche, D. Nemeschansky, N.P. Warner