@Article{ 
  MaNoPlRi15,
  author = { Martelli, Bruno and Novaga, Matteo and Pluda, Alessandra and Riolo, Stefano },
  title = { Spines of minimal length },
  journal = { Ann. Sc. Norm. Super. Pisa Cl. Sci. },
  year = { 2017 },
  doi = { 10.2422/2036-2145.201511_003 },
  volume = { XVII },
  pages = { 1067-1090 },
  URL = { http://cvgmt.sns.it/paper/2836/ },
  note = { cvgmt preprint}
}