@Misc{ 
  BraLin15,
  author = { Brasco, Lorenzo and Lindgren, Erik },
  title = { Higher Sobolev regularity for the fractional $p-$Laplace equation in the superquadratic case },
  journal = { Adv. Math. },
  year = { 2015 },
  pages = { 36 },
  URL = { http://cvgmt.sns.it/paper/2759/ },
  note = { cvgmt preprint}
}