PORTER MICHAEL E. (1980). COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDUSTRIES AND COMPETITORS. FREE PRESS.
Chicago-referens (17:e uppl.)PORTER MICHAEL E. COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDUSTRIES AND COMPETITORS. NEW YORK: FREE PRESS, 1980.
MLA-referens (9:e uppl.)PORTER MICHAEL E. COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDUSTRIES AND COMPETITORS. FREE PRESS, 1980.
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