APA aipamena

Stephen R. Covey. (2004). The 8th habit: From effectiveness to greatness. Free Press.

Chicago Style aipamena

Stephen R. Covey. The 8th Habit: From Effectiveness to Greatness. New York: Free Press, 2004.

MLA aipamena

Stephen R. Covey. The 8th Habit: From Effectiveness to Greatness. Free Press, 2004.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.