Stephen R Covey. (1989). Seven habits of highly effective people restoring the character ethic. Fireside.
Trích dẫn kiểu ChicagoStephen R Covey. Seven Habits of Highly Effective People Restoring the Character Ethic. New York: Fireside, 1989.
Trích dẫn MLAStephen R Covey. Seven Habits of Highly Effective People Restoring the Character Ethic. Fireside, 1989.
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