@Misc{ 
  FraPra16,
  author = { Franceschi, Valentina and Prandi, Dario and Rizzi, Luca },
  title = { Recent results on the essential self-adjointness of sub-Laplacians, with some remarks on the presence of characteristic points },
  journal = { Séminaire de Théorie spectrale et géométrie (Grenoble) },
  year = { 2016 },
  doi = { 10.5802/tsg.311 },
  volume = { 33 },
  pages = { 1-15 },
  URL = { http://cvgmt.sns.it/paper/4259/ },
  note = { cvgmt preprint}
}