Covey, S. R. (2004). 8th Habit from effectiveness to greatness (Audio Book). Simon & Schuster Inc.
Cita Chicago (17th ed.)Covey, Stephen R. 8th Habit from Effectiveness to Greatness (Audio Book). New York: Simon & Schuster Inc, 2004.
Cita MLA (9th ed.)Covey, Stephen R. 8th Habit from Effectiveness to Greatness (Audio Book). Simon & Schuster Inc, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.