@Misc{ 
  Mag2,
  author = { Magnani, Valentino },
  title = { Elements of Geometric Measure Theory on sub-Riemannian groups },
  journal = { Collana "Tesi" },
  year = { 2002 },
  pages = { 208 },
  URL = { http://cvgmt.sns.it/paper/1742/ },
  note = { cvgmt preprint}
}