APA-referens (7:e uppl.)

Covey, S. R. (1991). Principle-centered leadershipages (First edition.). A Fireside Book.

Chicago-referens (17:e uppl.)

Covey, Stephen R. Principle-centered Leadershipages. First edition. New York: A Fireside Book, 1991.

MLA-referens (9:e uppl.)

Covey, Stephen R. Principle-centered Leadershipages. First edition. A Fireside Book, 1991.