Citazione Stile APA (7a Edizione)

Covey, S. R. (2004). The seven habits of highly effective people ([2nd ed.].). Pocket Books.

Citazione stile Chigago Style (17a edizione)

Covey, Stephen R. The Seven Habits of Highly Effective People. [2nd ed.]. London: Pocket Books, 2004.

Citatione MLA (9a ed.)

Covey, Stephen R. The Seven Habits of Highly Effective People. [2nd ed.]. Pocket Books, 2004.