Style de citation APA (7e éd.)

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

Style de citation Chicago (17e éd.)

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

Style de citation MLA (9e éd.)

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