@article{KKLN1989J,
  author = {Jyrki Katajainen and Markku Koppinen and Timo Leip\"{a}l\"{a} and
    Olli Nevalainen},
  title = {Divide and conquer for the closest-pair problem revisited},
  journaltitle = {International Journal on Computer Mathematics},
  volume = {27},
  number = {3--4},
  year = {1989},
  pages = {121--132},
}