@Article{ 
  Fog23b,
  author = { Foghem, Guy },
  title = { Nonlocal characterization of Sobolev spaces },
  journal = { Partial Differential Equations and Applications },
  year = { 2023 },
  doi = { 10.1007/s42985-023-00232-4 },
  pages = { 27 },
  URL = { http://cvgmt.sns.it/paper/5943/ },
  note = { cvgmt preprint}
}