@article{Kowalski79,
  author = "Kowalski, Robert",
  title = "{Algorithm = Logic + Control}",
  journal = "Communications of the ACM",
  volume = "22",
  number = "7",
  month = "Jul.",
  year = "1979",
  url = "http://www.cs.berkeley.edu/~jcondit/pl-prelim/kowalski79logiccontrol.pdf",
}