@Misc{ 
  Spe19a,
  author = { Spector, Daniel },
  title = { A Noninequality for the Fractional Gradient },
  journal = {  },
  year = { 2019 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/4793/ },
  note = { cvgmt preprint}
}