@article{digitalTopology,
  title = "Concepts of digital topology",
  author = "A. W. Roscoe and T.Y. Kong",
  year = "1992",
  journal = "Topology and its applications",
  pages = "219--262",
  url = "http://www.cs.ox.ac.uk/people/bill.roscoe/publications/42.pdf",
  volume = "46",
}