@article{Gibbons2006:Spigot,
  title = "An Unbounded Spigot Algorithm for the Digits of $\pi$",
  author = "Jeremy Gibbons",
  year = "2006",
  journal = "American Mathematical Monthly",
  number = "4",
  pages = "318-328",
  url = "http://www.comlab.ox.ac.uk/oucl/work/jeremy.gibbons/publications/spigot.pdf",
  volume = "113",
}