Covey Stephen R. (2004). 7 Habits of highly effective people. Pocket Books.
Chicagoスタイル(17版)引用形式Covey Stephen R. 7 Habits of Highly Effective People. London: Pocket Books, 2004.
MLA(9版)引用形式Covey Stephen R. 7 Habits of Highly Effective People. Pocket Books, 2004.
警告: この引用は必ずしも正確ではありません.