Cita APA (7th ed.)

Porter M.E. (1980). Competitive Strategy. Free Press.

Cita Chicago (17th ed.)

Porter M.E. Competitive Strategy. New Delhi: Free Press, 1980.

Cita MLA (9th ed.)

Porter M.E. Competitive Strategy. Free Press, 1980.

Atenció: Aquestes cites poden no estar 100% correctes.