@Article{ 
  MonPigVit16,
  author = { Monti, Roberto and Pigati, Alessandro and Vittone, Davide },
  title = { Existence of tangent lines to Carnot-Carathéodory geodesics },
  journal = { Calc. Var. Partial Differential Equations 57 },
  year = { 2018 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/3175/ },
  note = { cvgmt preprint}
}