@Misc{ 
  JhaNeu17,
  author = { Jhaveri, Yash and Neumayer, Robin },
  title = { Higher regularity of the free boundary in the obstacle problem for the fractional Laplacian },
  journal = { Adv. Math. },
  year = { 2017 },
  volume = { 311 },
  pages = { 748--795 },
  URL = { http://cvgmt.sns.it/paper/3408/ },
  note = { cvgmt preprint}
}