Citazione Stile APA (7a Edizione)
Covey, S. R. (1990). <The> seven habits of highly effective people: Restoring the character ethic (1st Fireside ed.). Simon & Schuster.
Citazione stile Chigago Style (17a edizione)
Covey, Stephen R. <The> Seven Habits of Highly Effective People: Restoring the Character Ethic. 1st Fireside ed. New York: Simon & Schuster, 1990.
Citatione MLA (9a ed.)
Covey, Stephen R. <The> Seven Habits of Highly Effective People: Restoring the Character Ethic. 1st Fireside ed. Simon & Schuster, 1990.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.