@Misc{ 
  belbeopao,
  author = { Bellettini, Giovanni and Beorchia, Valentina and Paolini, Maurizio },
  title = { Topological and variational properties of a model for the reconstruction of three-dimensional transparent images with self-occlusions },
  journal = {  },
  year = { 2006 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/626/ },
  note = { cvgmt preprint}
}