APA-viite (7. p.)

PORTER MICHAEL. (2004). COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDUSTRIES AND COMPETITORS. THE FREE PRESS.

Chicago-viite (17. p.)

PORTER MICHAEL. COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDUSTRIES AND COMPETITORS. NEW YORK: THE FREE PRESS, 2004.

MLA-viite (9. p.)

PORTER MICHAEL. COMPETITIVE STRATEGY: TECHNIQUES FOR ANALYZING INDUSTRIES AND COMPETITORS. THE FREE PRESS, 2004.