@Misc{ 
  Gig13a,
  author = { Gigli, Nicola },
  title = { An overview on the proof of the splitting theorem in non-smooth context },
  journal = {  },
  year = { 2013 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2154/ },
  note = { cvgmt preprint}
}