Gaya APA

Covey, S, R. (1989). The 7 Habits of Highly Effective People: Powerful Lessons in Personal Change (Edisi 1). New York: Free Press.

Gaya MLA

Covey, Stephen, R.. "The 7 Habits of Highly Effective People: Powerful Lessons in Personal Change". Edisi 1 New York: Free Press, 1989. Text.