A Lecture on Neutrino Masses, Mixing and Oscillations
  Neutrino mixing and basics of neutrino oscillations are considered. Recent evidences in favour of neutrino oscillations, obtained in the solar and atmospheric neutrino experiments, are discussed. Neutrino oscillations in the solar and atmospheric ranges of $\Delta m^{2}$ are considered in the framework of the minimal scheme with the mixing of three massive neutrinos. 
S. M. Bilenky