@inproceedings{ijcai2009p341,
  title     = {Conjunctive Query Answering in the Description Logic EL Using a Relational Database System},
  author    = {Lutz, Carsten and Toman, David and Wolter, Frank},
  booktitle = {Proceedings of the Twenty-First International Joint Conference on
               Artificial Intelligence, {IJCAI-09}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Hiroaki Kitano},
  pages     = {2070--2074},
  year      = {2009},
  url       = {https://ijcai.org/proceedings/2009/341},
}