  A sample of Z decays containing b-flavoured hadrons is tagged using leptons,
and events having precise proper time measurements are selected. These events
are used to study Bs oscillations. using the lepton to tag the decay b-flavour
and jet charge or a second lepton, where available, to determine the produced
b-flavour. The flavour (b or b-bar) at decay is determined from the lepton
charge while the flavour at production is determined from jet charge or the
charge of a second lepton, where available. The experiment was not able to
resolve the oscillatory behaviour, and we deduce that the Bs oscillation
frequency Delta(ms)> 5.2ps-1 at the 95% confidence level.
