Superspace Geometrical Realization of the N-Extended Super Virasoro   Algebra and its Dual
  We derive properties of N-extended GR super Virasoro algebras. These include adding central extensions, identification of all primary fields and the action of the adjoint representation on its dual. The final result suggest identification with the spectrum of fields in supergravity theories and superstring/M-theory constructed from NSR N-extended supersymmetric ${\cal {GR}}$ Virasoro algebras. 
C. Curto, S.J. Gates, V. G. J. Rodgers