@Misc{ 
  Mon15,
  author = { Monti, Roberto },
  title = { Minimal surfaces and harmonic functions in the Heisenberg group },
  journal = { Nonlinear Analysis Series A: Theory, Methods & Applications },
  year = { 2015 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/2658/ },
  note = { cvgmt preprint}
}