Dyfyniad APA

Covey, S. R. (1991). Principle centered leadership. New York: A Fireside.

Dyfyniad Arddull Chicago

Covey, Stephen R. Principle Centered Leadership. New York: A Fireside, 1991.

Dyfyniad MLA

Covey, Stephen R. Principle Centered Leadership. New York: A Fireside, 1991.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.