@Misc{ 
  arecarcau08,
  author = { Arena, Gabriella and Caruso, Andrea Orazio and Causa, Antonio },
  title = { "Taylor Formula on step two Carnot groups" },
  journal = { Rev. Mat. Iberoamericana },
  year = { 2008 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/889/ },
  note = { cvgmt preprint}
}