Stephen R Covey. (1989). Seven habits of highly effective people. D C Books.
Chicago Edition CitationStephen R Covey. Seven Habits of Highly Effective People. Kottayam: D C Books, 1989.
MLA Edition CitationStephen R Covey. Seven Habits of Highly Effective People. D C Books, 1989.
Advarsel: Disse citationer er muligvist ikke 100% nøjagtige.