Covey, S. R. (1989). Seven habits of highly effective people: Restoring the character ethic.
استشهاد بنمط شيكاغوCovey, Stephen R. Seven Habits of Highly Effective People: Restoring the Character Ethic. Simon & Schuster: New York, 1989.
MLA استشهادCovey, Stephen R. Seven Habits of Highly Effective People: Restoring the Character Ethic. 1989.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.