PORTER MICHAEL E. (1998). COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDU AND COMPETITORS. FREE PRESS.
Cita Chicago (17th ed.)PORTER MICHAEL E. COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDU AND COMPETITORS. NEW YORK: FREE PRESS, 1998.
Cita MLA (9th ed.)PORTER MICHAEL E. COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDU AND COMPETITORS. FREE PRESS, 1998.
Atenció: Aquestes cites poden no estar 100% correctes.