@article{silva_kellerman_2007,  title={Analyzing the payoff of a heterogeneous population in the ultimatum game},  volume={37},  ISSN={0103-9733},  url={https://doi.org/10.1590/S0103-97332007000800003},  DOI={10.1590/S0103-97332007000800003},  number={4},  journal={Brazilian Journal of Physics},  publisher={Sociedade Brasileira de Física},  author={Silva, Roberto da and Kellerman, Gustavo Adolfo},  year={2007},  month={Dec},  pages={1206–1211} }