@article{Bird77:Improving,
  title = "Improving Programs by the Introduction of Recursion",
  author = "Richard S. Bird",
  year = "1977",
  journal = "Communications of the ACM",
  month = "nov",
  number = "11",
  pages = "856--863",
  volume = "20",
  doi = "10.1145/359863.359889",
}