@inproceedings{ijcai2001p99,
  title     = {A Fuzzy Modal Logic for Belief Functions},
  author    = {Godo, Lluís and Hájek, Petr and Esteva, Francesc},
  booktitle = {Proceedings of the Seventeenth International Joint Conference on
               Artificial Intelligence, {IJCAI-01}},
  publisher = {International Joint Conferences on Artificial Intelligence},
  pages     = {723--731},
  year      = {2001},
  url       = {https://ijcai.org/proceedings/2001/99},
}