Covey, S. R. (2004). The 7 Habits of Highly Effective People. Pocket Books.
Citazione stile Chigago Style (17a edizione)Covey, Stephen R. The 7 Habits of Highly Effective People. Pocket Books, 2004.
Citatione MLA (9a ed.)Covey, Stephen R. The 7 Habits of Highly Effective People. Pocket Books, 2004.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.