APA aipamena

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

Chicago Style aipamena

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

MLA aipamena

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

Kontuz: berrikusi erreferentzia hauek erabili aurretik.