Porter, M. E. (1980). Competitive strategy: Techniques for analyzing industries and competitors. Free Press.
Chicago-viite (17. p.)Porter, Michael E. Competitive Strategy: Techniques for Analyzing Industries and Competitors. New York: Free Press, 1980.
MLA-viite (9. p.)Porter, Michael E. Competitive Strategy: Techniques for Analyzing Industries and Competitors. Free Press, 1980.
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