Dunbar, R., & Botha, R. (2009). Why only humans have language. Oxford University Press.
Cita Chicago (17th ed.)Dunbar, R., i R. Botha. Why Only Humans Have Language. Oxford University Press, 2009.
Cita MLA (9th ed.)Dunbar, R., i R. Botha. Why Only Humans Have Language. Oxford University Press, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.