@Misc{ 
  MagCor20,
  author = { Corni, Francesca and Magnani, Valentino },
  title = { Area formula for regular submanifolds of low codimension in Heisenberg groups },
  journal = {  },
  year = { 2020 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/4573/ },
  note = { cvgmt preprint}
}