@Article{ 
  cagmormor07,
  author = { Cagnetti, Filippo and Mora, Maria Giovanna and Morini, Massimiliano },
  title = { A second order minimality condition for the Mumford-Shah functional },
  journal = { Calc. Var. },
  year = { 2008 },
  volume = { 33 },
  pages = { 37-74 },
  URL = { http://cvgmt.sns.it/paper/685/ },
  note = { cvgmt preprint}
}