singer, p. (1993). Practical Ethics (2nd.). cambridge University Press.
Cita Chicago Style (17a ed.)singer, peter. Practical Ethics. 2nd. Cambridge: cambridge University Press, 1993.
Cita MLA (9a ed.)singer, peter. Practical Ethics. 2nd. cambridge University Press, 1993.
Precaución: Estas citas no son 100% exactas.