@Misc{ 
  beldemdir,
  author = { Bellettini, Giovanni and De Masi, Anna and Dirr, Nicolas and Presutti, Errico },
  title = { Tunnelling in two dimensions },
  journal = { Comm. Math. Phys. },
  year = { 2006 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/612/ },
  note = { cvgmt preprint}
}