Covey, S. R. (1989). The 7 habits of highly effective people: Restoring the character ethic. Pocket books.
Chicago Style citaatCovey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. London: Pocket books, 1989.
MLA citatieCovey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. Pocket books, 1989.
Let op: Deze citaties zijn niet altijd 100% accuraat.