Comparative Study of $Z'$ Searches in $e^+e^-$ and $e^-e^-$ Scattering
  We consider indirect searches for additional neutral vector bosons in $e^+e^-$ and $e^-e^-$ collisions, and compare these two linear collider modes with similar analysis procedures and assumptions. Discovery limits and resolving power are discussed in a model independent way. 
Frank Cuypers (PSI)