Bilepton Resonance in Electron-Electron Scattering

Theoretical backgound for bileptonic gauge bosons is reviewed, both the SU(15) GUT model and the 3-3-1 model. Mass limits on bileptons are discussed coming from $e^+e^-$ scattering, polarized muon decay and muonium-antimuonium conversion. Discovery in $e^-e^-$ at a linear collider at low energy (100GeV) and high luminosity ($10^{33}/cm^2/s$) is emphasised.}