@article{Gibbons*2006:Enumerating,
  abstract = "We present a series of programs for enumerating the rational numbers without duplication, drawing on some elegant results of Neil Calkin, Herbert Wilf and Moshe Newman.",
  author = "Jeremy Gibbons and David Lester and Richard Bird",
  journal = "Journal of Functional Programming",
  number = "4",
  title = "Enumerating the Rationals",
  url = "http://www.comlab.ox.ac.uk/oucl/work/jeremy.gibbons/publications/rationals.pdf",
  volume = "16",
  year = "2006",
}