Singer, P. (1993). Practical ethics (2nd ed.). Cambridge University Press.
Chicago Style aipamenaSinger, Peter. Practical Ethics. 2nd ed. Cambridge: Cambridge University Press, 1993.
MLA aipamenaSinger, Peter. Practical Ethics. 2nd ed. Cambridge University Press, 1993.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.