Covey, S. R. (1989). The seven habits of highly effective people: Restoring the character ethic. Simon and Schuster.
Lua i Stíl Chicago (17ú heag.)Covey, Stephen R. The Seven Habits of Highly Effective People: Restoring the Character Ethic. New York: Simon and Schuster, 1989.
Lua MLA (8ú heag.)Covey, Stephen R. The Seven Habits of Highly Effective People: Restoring the Character Ethic. Simon and Schuster, 1989.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.