@Misc{ 
  butvar05,
  author = { Buttazzo, Giuseppe and Varchon, Nicolas },
  title = { On the Optimal Reinforcement of an Elastic Membrane },
  journal = {  },
  year = { 2005 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/1320/ },
  note = { cvgmt preprint}
}