Cita APA

Singer, P. 1. (2011). The expanding circle: Ethics, evolution, and moral progress. Princeton [etc.]: Princeton University Press.

Citación estilo Chicago

Singer, Peter 1946-. The Expanding Circle: Ethics, Evolution, and Moral Progress. Princeton [etc.]: Princeton University Press, 2011.

Cita MLA

Singer, Peter 1946-. The Expanding Circle: Ethics, Evolution, and Moral Progress. Princeton [etc.]: Princeton University Press, 2011.