@Article{
  lus07,
  author = { Luca Lussardi },
  title = { An approximation for the Mumford-Shah functional },
  journal = { Int. J. Contemp. Math. Sci. },
  year = { 2007 },
  volume = { 2 },
  number = { 25 },
  pages = { 1237-1245 },
}