Covey, S. R. The 7 habits of highly effective people: Restoring the character ethic (Revised edition.).
Chicago (17e ed.) BronvermeldingCovey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. Revised edition.
MLA (8e ed.) BronvermeldingCovey, Stephen R. The 7 Habits of Highly Effective People: Restoring the Character Ethic. Revised edition.
Let op: Deze citaties zijn niet altijd 100% accuraat.