@Article{ 
  BalFraTri15,
  author = { Baldi, Annalisa and Franchi, Bruno and Tripaldi, Francesca },
  title = { Gagliardo-Nirenberg Inequalities for Horizontal Vector Fields in the Engel Group and in the Seven-Dimensional Quaternionic Heisenberg Group },
  journal = { Geometric Methods in PDE’s. Springer INdAM Series },
  year = { 2015 },
  doi = { https://doi.org/10.1007/978-3-319-02666-4_16 },
  volume = { 13 },
  pages = {  },
  URL = { http://cvgmt.sns.it/paper/5862/ },
  note = { cvgmt preprint}
}