@Misc{ AgrBarBos17, author = { Agrachev, Andrei and Barilari, Davide and Boscain, Ugo }, title = { A Comprehensive Introduction to Sub-Riemannian Geometry }, journal = { Cambridge Studies in Advanced Mathematics, Cambridge Univ. Press }, year = { 2019 }, volume = { 181 }, pages = { 762 }, URL = { http://cvgmt.sns.it/paper/3664/ }, note = { cvgmt preprint} }