Gaya APA
RACHELS, J., RACHELS, S.
(2010).
The elements of moral philosophy
(
6th ed.)
.
Boston Burr Ridge:
McGraw Hill.
Gaya MLA
RACHELS, James., RACHELS, Stuart.
"The elements of moral philosophy".
6th ed.
Boston Burr Ridge:
McGraw Hill,
2010.
Buku.