Covey, S. R. (1999). Seven habits of highly effective people (1st.). Pocket books.
Chicago ZitierstilCovey, Stephen R. Seven Habits of Highly Effective People. 1st. London: Pocket books, 1999.
MLA ZitierstilCovey, Stephen R. Seven Habits of Highly Effective People. 1st. Pocket books, 1999.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.