Porter, M. E. (1998). Competitive strategy: Techniques for analyzing industries and competitors : with a new introduction (1st Free Press ed.). New York: Free Press.
Παραπομπή Chicago StylePorter, Michael E. Competitive Strategy: Techniques for Analyzing Industries and Competitors : With a New Introduction. 1st Free Press ed. New York: Free Press, 1998.
Παραπομπή MLAPorter, Michael E. Competitive Strategy: Techniques for Analyzing Industries and Competitors : With a New Introduction. 1st Free Press ed. New York: Free Press, 1998.
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