@Misc{ 
  DipSoaVal16,
  author = { Dipierro, Serena and Soave, Nicola and Valdinoci, Enrico },
  title = { On fractional elliptic equations in Lipschitz sets and epigraphs: regularity, monotonicity and rigidity results. },
  journal = { Mathematische Annalen },
  year = { 2016 },
  doi = { 10.1007/s00208-016-1487-x },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/3258/ },
  note = { cvgmt preprint}
}