Covey, S. R. (1999). Seven habits of highly effective people (1st.). Pocket books.
シカゴスタイル引用形Covey, Stephen R. Seven Habits of Highly Effective People. 1st. London: Pocket books, 1999.
MLA引用形式Covey, Stephen R. Seven Habits of Highly Effective People. 1st. Pocket books, 1999.
警告: この引用は必ずしも正確ではありません.