singer, p. (1993). Practical Ethics (2nd.). cambridge University Press.
Chicago Style (17th ed.) Citationsinger, peter. Practical Ethics. 2nd. Cambridge: cambridge University Press, 1993.
MLA (9th ed.) Citationsinger, peter. Practical Ethics. 2nd. cambridge University Press, 1993.
Advarsel: Disse citationer er muligvist ikke 100% nøjagtige.