@Article{ 
  del01b,
  author = { Delladio, Silvano },
  title = { A criterion for $C^2$-rectifiability of sets },
  journal = { Ann. Mat. Pura ed Appl. },
  year = { 2003 },
  volume = { 182 },
  number = { 3 },
  pages = { 357-373 },
  URL = { http://cvgmt.sns.it/paper/1248/ },
  note = { cvgmt preprint}
}