Measurements of Four-Fermion Production via Neutral Elektroweak Currents   at LEP
  Four-fermion production via electroweak neutral currents has been measured by all four LEP collaborations at center-of-mass energies near the Z resonance and for the first time also at energies well above the Z peak. Essentially all possible final states have been covered in four different topologies. 
Michael Kobel, representing the four LEP collaborations ALEPH, DELPHI,   L3, and OPAL