@Article{ 
  daltoa04,
  author = { Dal Maso, Gianni and Toader, Rodica },
  title = { On a notion of unilateral slope for the Mumford-Shah functional },
  journal = { NoDEA Nonlinear Differential Equations Appl. },
  year = { 2007 },
  volume = { 13 },
  pages = { 713-734 },
  URL = { http://cvgmt.sns.it/paper/404/ },
  note = { cvgmt preprint}
}