@article{CTT100762767,
  author = {Hayato Shimura and Mayuko Nakamaru},
  title = {Large group size promotes the evolution of cooperation in the mutual-aid game},
  journal = {Journal of theoretical biology},
  year = 2018,
}

@article{CTT100754387,
  author = {Mayuko Nakamaru and Hayato Shimura and Yoko Kitakaji and Susumu Ohnuma},
  title = {The effect of sanctions on the evolution of cooperation in linear division of labor},
  journal = {Journal of theoretical biology},
  year = 2018,
}