Stephen R Covey. (1989). Seven habits of highly effective people. D C Books.
Chicago ZitierstilStephen R Covey. Seven Habits of Highly Effective People. Kottayam: D C Books, 1989.
MLA ZitierstilStephen R Covey. Seven Habits of Highly Effective People. D C Books, 1989.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.