@article{BirdRavelo97:On,
  title = "On Computing Representatives",
  author = "Richard S. Bird and Jes{\'u}s N. Ravelo",
  year = "1997",
  journal = "Information Processing Letters",
  pages = "1--7",
  volume = "63",
  doi = "10.1016/S0020-0190(97)00087-2",
}