  Searches for resonant sneutrino production in e+e- collisions under the
assumption that R-parity is not conserved and that the dominant R-parity
violating coupling is lambda_{121} or lambda_{131} used data recorded by DELPHI
in 1997 to 2000 at centre-of-mass energies of 183 to 208 GeV. No deviation from
the Standard Model was observed. Upper limits are given for the lambda_{121}
and lambda_{131} couplings as a function of the sneutrino mass and total width.
The limits are especially stringent for sneutrino masses equal to the
centre-of-mass energies with the highest integrated luminosities recorded.
