Dyfyniad APA

Covey, S. R. (2004). 7 habits of highly effective people. Pocket books.

Dyfyniad Arddull Chicago

Covey, Stephen R. 7 Habits of Highly Effective People. London: Pocket books, 2004.

Dyfyniad MLA

Covey, Stephen R. 7 Habits of Highly Effective People. Pocket books, 2004.

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