@Article{ 
  MonPigVit17,
  author = { Monti, Roberto and Pigati, Alessandro and Vittone, Davide },
  title = { On tangent cones to length minimizers in Carnot-Carathéodory spaces },
  journal = { SIAM J. Control Optim. 56 (2018) },
  year = { 2018 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/3529/ },
  note = { cvgmt preprint}
}