@misc{indiciae202ad07566b9,
  title = {Evolution of cooperation by multilevel selection.},
  author = {Arne Traulsen and Martin A Nowak},
  year = {2006},
  doi = {10.1073/pnas.0602530103},
  url = {https://pubmed.ncbi.nlm.nih.gov/16829575/},
  note = {Source identifier: 16829575}
}