@Misc{ 
  leo09,
  author = { Leoni, Giovanni },
  title = { A First Course in Sobolev Spaces },
  journal = { Graduate Studies in Mathematics, American Mathematical Society },
  year = { 2009 },
  volume = { 105 },
  pages = { 607 },
  URL = { http://cvgmt.sns.it/paper/937/ },
  note = { cvgmt preprint}
}