APA citiranje

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

Trích dẫn kiểu Chicago

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

MLA citiranje

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