@article{Gibbons96:Deriving,
  title = "Deriving Tidy Drawings of Trees",
  author = "Jeremy Gibbons",
  year = "1996",
  journal = "Journal of Functional Programming",
  number = "3",
  pages = "535--562",
  url = "http://www.cs.ox.ac.uk/people/jeremy.gibbons/publications/drawing.ps.gz",
  volume = "6",
}