  This paper is concerned with discrete, uniform subgroups (lattices) of
oscillator groups, which are certain semidirect products of the Heisenberg
group and the additive group of real numbers. The present paper rectifies the
uncertainties in [1] of Medina and Revoy and gives a complete classification of
the lattices of the 4-dimensional oscillator group up to isomorphism.
  [1] Medina, A.; Revoy, P. Les groups oscillateurs et leurs reseaux
Manuscripta Mathematica, 1985, 52, 81-95
