Gaya APA
Covey, S. (1990).
The 7 Habits of Highly Effective People: Restoring the Character Ethic .
New York:
A Fireside Book/Simon & Schuster.
Gaya MLA
Covey, Stephen.
"The 7 Habits of Highly Effective People: Restoring the Character Ethic".
New York:
A Fireside Book/Simon & Schuster,
1990.
Book.