Dyfyniad APA
Covey Stephen R. (2004). The 7 habits of highly effective people. Pocket Books.
Dyfyniad Arddull Chicago
Covey Stephen R. The 7 Habits of Highly Effective People. New York: Pocket Books, 2004.
Dyfyniad MLA
Covey Stephen R. The 7 Habits of Highly Effective People. Pocket Books, 2004.
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