@Misc{ 
  BarFigVal12,
  author = { Barrios, Begoña and Figalli, Alessio and Valdinoci, Enrico },
  title = { Bootstrap regularity for integro-differential operators and its application to nonlocal minimal surfaces },
  journal = { Ann. Scuola Norm. Sup. Pisa Cl. Sci. },
  year = { 2012 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/1894/ },
  note = { cvgmt preprint}
}