@Misc{ 
  ManPicPol21,
  author = { Manfredini, Maria and Piccinini, Mirco and Polidoro, Sergio },
  title = { The Dirichlet problem for a family of totally degenerate differential  operators },
  journal = {  },
  year = { 2021 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/5668/ },
  note = { cvgmt preprint}
}