Lorenz or Coulomb in Galilean Electromagnetism ?
  Galilean Electromagnetism was discovered thirty years ago by Levy-Leblond & Le Bellac. However, these authors only explored the consequences for the fields and not for the potentials. Following De Montigny & al., we show that the Coulomb gauge condition is the magnetic limit of the Lorenz gauge condition whereas the Lorenz gauge condition applies in the electric limit of L\'{e}vy-Leblond & Le Bellac. Contrary to De Montigny & al. who used Galilean tensor calculus, we use orders of magnitude based on physical motivations in our derivation. 
Germain Rousseaux (INLN)