@Article{ 
  SpoDePVel19,
  author = { De Philippis, Guido and Spolaor, Luca and Velichkov, Bozhidar },
  title = { Regularity of the free boundary for the two-phase Bernoulli problem },
  journal = { Inventiones mathematicae },
  year = { 2021 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/4513/ },
  note = { cvgmt preprint}
}