@inproceedings{ijcai2020p19,
  title     = {Proportionality in Approval-Based Elections With a Variable Number of Winners},
  author    = {Freeman, Rupert and Kahng, Anson and Pennock, David M.},
  booktitle = {Proceedings of the Twenty-Ninth International Joint Conference on
               Artificial Intelligence, {IJCAI-20}},
  publisher = {International Joint Conferences on Artificial Intelligence Organization},
  editor    = {Christian Bessiere},
  pages     = {132--138},
  year      = {2020},
  month     = {7},
  note      = {Main track},
  doi       = {10.24963/ijcai.2020/19},
  url       = {https://doi.org/10.24963/ijcai.2020/19},
}