@inproceedings{ijcai1989p207,
  title     = {Approximation Algorithms for Temporal Reasoning},
  author    = {van Beek, Peter},
  booktitle = {Proceedings of the Eleventh International Joint Conference on
               Artificial Intelligence, {IJCAI-89}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {N. S. Sridharan},
  pages     = {1291--1295},
  year      = {1989},
  month     = {8},
  note      = {Knowledge Representation},
  url       = {https://ijcai.org/proceedings/1989/207},
}