Covey, S. R. (2004). 7 habits of highly effective people. Pocket books.
Chicago ZitierstilCovey, Stephen R. 7 Habits of Highly Effective People. London: Pocket books, 2004.
MLA ZitierstilCovey, Stephen R. 7 Habits of Highly Effective People. Pocket books, 2004.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.