@article{journals/scp/CurtisL96,
  title = "Proofs with Graphs",
  author = "Sharon Curtis and Gavin Lowe",
  year = "1996",
  journal = "Sci. Comput. Program.",
  number = "1-3",
  pages = "197-216",
  url = "http://cms.brookes.ac.uk/staff/SharonCurtis/publications/graphSCP.ps.gz",
  volume = "26",
}