APA (7th ed.) Zitazioa
Covey, S. R. (2004). The 7 habits of highly effective people. Pocket Books.
Chicago Style (17th ed.) Zitazioa
Covey, Stephen R. The 7 Habits of Highly Effective People. London: Pocket Books, 2004.
MLA (9th ed.) Zitazioa
Covey, Stephen R. The 7 Habits of Highly Effective People. Pocket Books, 2004.
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