@Misc{ 
  capgar01,
  author = { Capogna, Luca and Garofalo, Nicola },
  title = { Regularity of minimizers of the calculus of variations in Carnot groups via hypoellipticity of systems of Hörmander type  },
  journal = { Journal of the European Mathematical Society },
  year = { 2001 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/978/ },
  note = { cvgmt preprint}
}