1. How altruism can prevail in an evolutionary environment;Bergstrom;American Economic Review Papers and Proceedings,1993
2. The Origin and Evolution of Cultures;Boyd,2004
3. Endogenous group formation and public goods provision: exclusion, exit, mergers, and redemption;Charness,2007
4. Croson, R., Fatas, E., Neugebauer, T., 2006. Excludability and contribution: a laboratory study in team production. Working Paper, the Wharton School.
5. The Selfish Gene;Dawkins,1976