Cita APA (7a ed.)

Porter, M. E. (1980). Competitive strategy: Techniques for analyzing industries and competitors /Michael E. Porter. The Free Press.

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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