Dyfyniad APA

Covey, S. R. (2013). The 7 Habits of Highly Effective People. Simon & Schuster.

Dyfyniad Arddull Chicago

Covey, Stephen R. The 7 Habits of Highly Effective People. UK: Simon & Schuster, 2013.

Dyfyniad MLA

Covey, Stephen R. The 7 Habits of Highly Effective People. Simon & Schuster, 2013.

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