@Misc{ 
  capgar03,
  author = { Capogna, Luca and Garofalo, Nicola },
  title = { Ahlfors regularity in Carnot-Carathéodory spaces },
  journal = {  },
  year = { 2003 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/724/ },
  note = { cvgmt preprint}
}