@Misc{ 
  DanOgn21,
  author = { Danielli, Donatella and Ognibene, Roberto },
  title = { On a weighted two-phase boundary obstacle problem },
  journal = { Indiana University Mathematics Journal },
  year = { 2021 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/5308/ },
  note = { cvgmt preprint}
}