APA aipamena

Porter, M. (2004). Competitive Advantage (1st.). Free Press.

Chicago Style aipamena

Porter, Michael. Competitive Advantage. 1st. Free Press, 2004.

MLA aipamena

Porter, Michael. Competitive Advantage. 1st. Free Press, 2004.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.