APA aipamena

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

Chicago Style aipamena

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

MLA aipamena

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

Kontuz: berrikusi erreferentzia hauek erabili aurretik.