@inproceedings{ijcai1993p34,
  title     = {Why AC-3 is Almost Always Better than AC4 for Establishing Arc Consistency in CSPs},
  author    = {Wallace, Richard J.},
  booktitle = {Proceedings of the Thirteenth International Joint Conference on
               Artificial Intelligence, {IJCAI-93}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Ruzena Bajcsy},
  pages     = {239--246},
  year      = {1993},
  note      = {Constraint Satisfaction Problems},
  url       = {https://ijcai.org/proceedings/1993/34},
}