@Misc{ LeDRig14, author = { Le Donne, Enrico and Rigot, Severine }, title = { Besicovitch Covering Property for homogeneous distances in the Heisenberg groups }, journal = { }, year = { 2014 }, pages = { }, URL = { http://cvgmt.sns.it/paper/2471/ }, note = { cvgmt preprint} }