Gaya APA

Covey, S, R. (2004). The 7 Habits of Highly Effective People: Powerful Lessons in Personal Change . New York: SIMON & SCHUSTER.

Gaya MLA

Covey, Stephen, R. "The 7 Habits of Highly Effective People: Powerful Lessons in Personal Change". New York: SIMON & SCHUSTER, 2004. Text.