Covey, S. R. A. (2004). The 8th habit: From effectiveness to greatness.
シカゴスタイル引用形Covey, Stephen R; Author. The 8th Habit: From Effectiveness to Greatness. New York, Simon& Schuster, 2004.
MLA引用形式Covey, Stephen R; Author. The 8th Habit: From Effectiveness to Greatness. 2004.
警告: この引用は必ずしも正確ではありません.