@inproceedings{ijcai1989p1,
  title     = {Symbols and Subsymbols for Representing Knowledge: A Catalogue Raisonné},
  author    = {Frixione, Marcello and Spinelli, Giuseppe and Gaglio, Salvatore},
  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     = {3--6},
  year      = {1989},
  month     = {8},
  note      = {Foundations},
  url       = {https://ijcai.org/proceedings/1989/1},
}