APA aipamena

Westbrook, C., & Carolyn Westbrook. (2014). Unlock: Listening and speaking skills. Cambridge: Cambridge University Press.

Chicago Style aipamena

Westbrook, Carolyn, và Carolyn Westbrook. Unlock: Listening and Speaking Skills. Cambridge: Cambridge University Press, 2014.

MLA aipamena

Westbrook, Carolyn, và Carolyn Westbrook. Unlock: Listening and Speaking Skills. Cambridge: Cambridge University Press, 2014.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.