@Article{ 
  ciafusmag07,
  author = { Cianchi, Andrea and Fusco, Nicola and Maggi, Francesco and Pratelli, Aldo },
  title = { The sharp Sobolev inequality in quantitative form },
  journal = { Journal of the European Mathematical Society },
  year = { 2007 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/784/ },
  note = { cvgmt preprint}
}