@Misc{ 
  farval09a,
  author = { Farina, Alberto and Valdinoci, Enrico },
  title = { A pointwise gradient estimate in possibly unbounded domains with nonnegative mean curvature     },
  journal = { Advances in Mathematics },
  year = { 2009 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/1099/ },
  note = { cvgmt preprint}
}