@Misc{ 
  monric06,
  author = { Monti, Roberto and Rickly, Matthieu },
  title = { Convex isoperimetric sets in the Heisenberg group },
  journal = { Ann. Scuola Norm. Sup. Pisa Cl. Sci. },
  year = { 2008 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/1628/ },
  note = { cvgmt preprint}
}