@Misc{ 
  LeDHak16,
  author = { Hakavuori, Eero and Le Donne, Enrico },
  title = { Non-minimality of corners in subriemannian geometry },
  journal = { Inventiones Math.  },
  year = { 2016 },
  pages = { 11 },
  URL = { http://cvgmt.sns.it/paper/2973/ },
  note = { cvgmt preprint}
}