@Misc{ 
  LerBoa15,
  author = { Boarotto, Francesco and Lerario, Antonio },
  title = { Homotopy properties of horizontal path spaces and a theorem of Serre in subriemannian geometry },
  journal = {  },
  year = { 2015 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2888/ },
  note = { cvgmt preprint}
}