@Misc{ 
  FraMon14,
  author = { Franceschi, Valentina and Monti, Roberto },
  title = { Isoperimetric Problem in H-type groups and Grushin spaces },
  journal = { Revista Matemática Iberoabericana },
  year = { 2014 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2570/ },
  note = { cvgmt preprint}
}