APA način citiranja

O'Neill, R., & Richard O'Neill. (2014). Unlock: Listening and speaking skills. Cambridge: Cambridge University Press.

Čikaški stil citiranja

O'Neill, Richard, i Richard O'Neill. Unlock: Listening and Speaking Skills. Cambridge: Cambridge University Press, 2014.

MLA način citiranja

O'Neill, Richard, i Richard O'Neill. Unlock: Listening and Speaking Skills. Cambridge: Cambridge University Press, 2014.