@Misc{ 
  BonLemMil16,
  author = { Bonnivard, Matthieu and Lemenant, Antoine and Millot, Vincent },
  title = { On a phase field approximation of the planar Steiner problem: Existence, regularity, and asymptotic of minimizers },
  journal = {  },
  year = { 2016 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/3239/ },
  note = { cvgmt preprint}
}