@Misc{ 
  leomon06,
  author = { Leonardi, Gian Paolo and Monti, Roberto },
  title = { End-point equations and regularity of sub-Riemannian geodesics },
  journal = { GAFA },
  year = { 2006 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/1363/ },
  note = { cvgmt preprint}
}