@article{bisimulationandexpressivityforconditiona,
  title = {Bisimulation and expressivity for conditional belief, degrees of belief, and safe belief},
  author = {Mikkel Birkegaard Andersen and Thomas Bolander and Hans van Ditmarsch and Martin Holm Jensen},
  year = {2015},
  eprint = {1506.07990},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1506.07990v2},
}