Only Three
  It is shown that it is possible to account for all experimental indications for neutrino oscillations with just three flavours. In particular we suggest that the atmospheric neutrino anomaly and the LSND result can be explained by the same mass difference and mixing. Possible implications and future tests of the resulting mass and mixing pattern are given. 
Gabriela Barenboim and Florian Scheck (Mainz University)