Dyfyniad APA

Covey, S. (1992). The seven habits of highly effective people. Simon & Schuster.

Dyfyniad Arddull Chicago

Covey, Stephen. The Seven Habits of Highly Effective People. London: Simon & Schuster, 1992.

Dyfyniad MLA

Covey, Stephen. The Seven Habits of Highly Effective People. Simon & Schuster, 1992.

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