APA aipamena

PORTER, M. E. (1980). Competitive Strategy. the Free Press.

Chicago Style aipamena

PORTER, Michael E. Competitive Strategy. the Free Press, 1980.

MLA aipamena

PORTER, Michael E. Competitive Strategy. the Free Press, 1980.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.