@inproceedings{ijcai1991p69,
  title     = {Tractable Concept Languages},
  author    = {Donini, Francesco M. and Lenzerini, Maurizio and Nardi, Daniele and Nutt, Werner},
  booktitle = {Proceedings of the Twelfth International Joint Conference on
               Artificial Intelligence, {IJCAI-91}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {John Mylopoulos and Ray Reiter},
  pages     = {458--464},
  year      = {1991},
  month     = {8},
  note      = {Knowledge Representation},
  url       = {https://ijcai.org/proceedings/1991/69},
}