APA ציטוט

Covey, S. R. (1991). Principle-centered leadership. New York: Simon and Schuster.

Trích dẫn kiểu Chicago

Covey, Stephen R. Principle-centered Leadership. New York: Simon and Schuster, 1991.

ציטוט MLA

Covey, Stephen R. Principle-centered Leadership. New York: Simon and Schuster, 1991.