Covey, S. R. (2004). 7 habits of highly effective people. Pocket books.
Chicago Style citaatCovey, Stephen R. 7 Habits of Highly Effective People. London: Pocket books, 2004.
MLA citatieCovey, Stephen R. 7 Habits of Highly Effective People. Pocket books, 2004.
Let op: Deze citaties zijn niet altijd 100% accuraat.