@Misc{ 
  SpeVan18,
  author = { Spector, Daniel and Van Schaftingen, Jean },
  title = { Optimal embeddings into Lorentz spaces for some vector differential operators via Gagliardo's lemma },
  journal = {  },
  year = { 2018 },
  pages = { 20 },
  URL = { http://cvgmt.sns.it/paper/4100/ },
  note = { cvgmt preprint}
}