Swan, M., & Walter, C. (1991). The Cambridge English Course: T. I. Practice Book. New York: Cambridge University Press.
Chicago Style aipamenaSwan, Michael, và Catherine Walter. The Cambridge English Course: T. I. Practice Book. New York: Cambridge University Press, 1991.
MLA aipamenaSwan, Michael, và Catherine Walter. The Cambridge English Course: T. I. Practice Book. New York: Cambridge University Press, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.