APA (7e ed.) Bronvermelding

Porter, M. E. (1980). Competitive strategy: techniques for analyzing: Industries and competitors. Collier Macmillan.

Chicago (17e ed.) Bronvermelding

Porter, Michael E. Competitive Strategy: Techniques for Analyzing: Industries and Competitors. London: Collier Macmillan, 1980.

MLA (9e ed.) Bronvermelding

Porter, Michael E. Competitive Strategy: Techniques for Analyzing: Industries and Competitors. Collier Macmillan, 1980.