@Misc{ 
  DiMSqu18,
  author = {  ,   and Di Marino, Simone and Squassina, Marco },
  title = { New characterizations of Sobolev metric spaces },
  journal = {  },
  year = { 2018 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/3791/ },
  note = { cvgmt preprint}
}