Covey, S. R. (1991). Principle-centered leadership. New York: Simon and Schuster.
シカゴスタイル引用形Covey, Stephen R. Principle-centered Leadership. New York: Simon and Schuster, 1991.
MLA引用形式Covey, Stephen R. Principle-centered Leadership. New York: Simon and Schuster, 1991.
警告: この引用は必ずしも正確ではありません.