Cita APA (7th ed.)

Palmer, D. (2006). Why it's hard to be good: An introduction to ethical theory. McGraw-Hill.

Cita Chicago (17th ed.)

Palmer, Donald. Why It's Hard to Be Good: An Introduction to Ethical Theory. Boston: McGraw-Hill, 2006.

Cita MLA (9th ed.)

Palmer, Donald. Why It's Hard to Be Good: An Introduction to Ethical Theory. McGraw-Hill, 2006.