@Article{
  lus07a,
  author = { Luca Lussardi },
  title = { An approximation result for free discontinuity functionals by means of non-local energies },
  journal = { Math. Meth. Appl. Sci. },
  year = { 2008 },
  volume = { 31 },
  number = { 18 },
  pages = { 2133-2146 },
}