@Misc{ 
  ModSzé17,
  author = { Modena, Stefano and Székelyhidi, László Jr },
  title = { Non-uniqueness for the transport equation with Sobolev vector fields },
  journal = {  },
  year = { 2017 },
  pages = { 30 },
  URL = { http://cvgmt.sns.it/paper/3700/ },
  note = { cvgmt preprint}
}