@Article{ 
  sil,
  author = { Delladio, Silvano },
  title = { The projection of a rectifiable Legendrian set is $C^2$-rectifiable: a simplified proof },
  journal = { Proc. Royal Soc. Edinburgh. },
  year = { 2003 },
  volume = { 133 },
  pages = { 85-96 },
  URL = { http://cvgmt.sns.it/paper/1504/ },
  note = { cvgmt preprint}
}