Cita APA (7th ed.)

Porter Michael E. (1980). Competitve Strategy: Techniques for Analyzing Industries and Competitors. Free Press.

Cita Chicago (17th ed.)

Porter Michael E. Competitve Strategy: Techniques for Analyzing Industries and Competitors. New York: Free Press, 1980.

Cita MLA (9th ed.)

Porter Michael E. Competitve Strategy: Techniques for Analyzing Industries and Competitors. Free Press, 1980.