@Misc{ 
  Ler11,
  author = { Lerario, Antonio },
  title = { Homology invariants of quadratic maps },
  journal = { Sissa Digital Library },
  year = { 2011 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2890/ },
  note = { cvgmt preprint}
}