  Neutral triple-gauge-boson couplings ZZZ, ZZgam and Zgamgam have been studied
with the DELPHI detector using data at energies between 183 and 208 GeV. Limits
are derived on these couplings from an analysis of the reactions e+e- -> Zgam,
using data from the final states gamma f fbar, with f = q or neutrino, from
e+e- -> ZZ, using data from the four-fermion final states q qbar q qbar, q qbar
mu+ mu-, q qbar e+ e-, q qbar nu nubar, mu+ mu- nu nubar and e+ e- nu nubar,
and from e+e- -> Zgam*, in which the final state gamma is off mass-shell, using
data from the four-fermion final states q qbar e+ e- and q qbar mu+ mu-. No
evidence for the presence of such couplings is observed, in agreement with the
predictions of the Standard Model.
