APA (7th ed.) Zitazioa

Porter, M. E. (1985). Competitive advantage: Creating and sustaining superior performance. The Free Press.

Chicago Style (17th ed.) Zitazioa

Porter, Michael E. Competitive Advantage: Creating and Sustaining Superior Performance. New York: The Free Press, 1985.

MLA (9th ed.) Zitazioa

Porter, Michael E. Competitive Advantage: Creating and Sustaining Superior Performance. The Free Press, 1985.