@inproceedings{ijcai2001p7,
  title     = {A Spatial Odyssey of the Interval Algebra: 1. Directed Intervals},
  author    = {Renz, Jochen},
  booktitle = {Proceedings of the Seventeenth International Joint Conference on
               Artificial Intelligence, {IJCAI-01}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  pages     = {51--55},
  year      = {2001},
  url       = {https://ijcai.org/proceedings/2001/7},
}