@Misc{ 
  Leo17,
  author = { Leoni, Giovanni },
  title = { A First Course in Sobolev Spaces: Second Edition },
  journal = { AMS Graduate Studies in Mathematics },
  year = { 2017 },
  volume = { 181 },
  pages = { 734 },
  URL = { http://cvgmt.sns.it/paper/4017/ },
  note = { cvgmt preprint}
}