Z Boson Pair Production in e+e- Collisions at sqrt(s) = 183 and 189 GeV        
  
A study of Z boson pair production in e+e- annihilation at                     
center-of-mass energies near 183 GeV and 189 GeV is reported.                  
Final states containing only leptons, (llll and llnunu)                        
quark and lepton pairs (qqll and qqnunu) and only quarks (qqqq) have           
been studied.  In all states with at least one Z boson decaying                
hadronically, qq and bb final states are considered separately using           
lifetime and event-shape tags, thereby improving the cross-section             
measurement.  The Z-pair cross section is measured at energies between         
183 and 189 GeV.  Limits on anomalous ZZgamma and ZZZ couplings are            
derived.                                                                       
  
 Parallel session :5                   
 Plenary  session :6a