1. The evolution of social behavior.;Annual Review of Ecology and Systematics,1974
2. Social transmission and the spread of modern contraception in rural Ethiopia.;PLoS One,2011
3. Fertility, parental investment, and the early adoption of modern contraception in rural Ethiopia.;American Journal of Human Biology,2013
4. Ecological variation in wealth-fertility relationships in Mongolia: The ‘central theoretical problem of sociobiology’ not a problem after all?;Proceedings of the Royal Society B: Biological Sciences,2014