@Article{
  MaNoPlRi15,
  author = { Bruno Martelli and Matteo Novaga and Alessandra Pluda and Stefano Riolo },
  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 },
}