Covey, S. R. The 7 habits of highly effective people: Restoring the character ethic (Revised edition.).
Cita Chicago (17th ed.)Covey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. Revised edition.
Cita MLA (8th ed.)Covey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. Revised edition.
Atenció: Aquestes cites poden no estar 100% correctes.