@inproceedings{ijcai1997p20,
  title     = {A Four-Valued Fuzzy Propositional Logic},
  author    = {Straccia, Umberto},
  booktitle = {Proceedings of the Fifteenth International Joint Conference on
               Artificial Intelligence, {IJCAI-97}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  editor    = {Martha E. Pollack},
  pages     = {128--134},
  year      = {1997},
  note      = {Automated Reasoning},
  url       = {https://ijcai.org/proceedings/1997/20},
}