Oster, S. M. (1994). Modern competitive analysis (2nd ed.). University press.
Chicago Style aipamenaOster, Sharon M. Modern Competitive Analysis. 2nd ed. New York: University press, 1994.
MLA aipamenaOster, Sharon M. Modern Competitive Analysis. 2nd ed. University press, 1994.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.