@Misc{ 
  LeDRig15,
  author = { Le Donne, Enrico and Rigot, Severine },
  title = { Besicovitch Covering Property on graded groups and applications to measure differentiation },
  journal = {  },
  year = { 2015 },
  pages = { 56 },
  URL = { http://cvgmt.sns.it/paper/2861/ },
  note = { cvgmt preprint}
}