@Misc{ 
  NgPiSqVe17,
  author = { Nguyen, Hoai-Minh and Pinamonti, Andrea and Squassina, Marco and Vecchi, Eugenio },
  title = { New characterizations of magnetic Sobolev spaces },
  journal = {  },
  year = { 2017 },
  pages = { 21 },
  URL = { http://cvgmt.sns.it/paper/3377/ },
  note = { cvgmt preprint}
}