Covey, S. R. (2004). The 8th habit: From effectiveness to greatness. Free Press.
Chicagoスタイル(17版)引用形式Covey, Stephen R. The 8th Habit: From Effectiveness to Greatness. New York: Free Press, 2004.
MLA(8版)引用形式Covey, Stephen R. The 8th Habit: From Effectiveness to Greatness. Free Press, 2004.
警告: この引用は必ずしも正確ではありません.