- Stefania Gnesi, Ugo Montanari, and Alberto Martelli. Dynamic programming as graph searching: An algebraic approach. Journal of the ACM, 28(4):737-751, October 1981.
- Joxan Jaffar and Jean-Louis Lassez. Constraint logic programming. In Conference Record of the Fourteenth Annual ACM Symposium on Principles of Programming Languages, pages 111-119, Munich, Germany, January 1987.