APA aipamena

Ostrowska, S., & Sabina Ostrowska. (2014). Unlock: Listening and speaking skills. Cambridge: Cambridge University Press.

Chicago Style aipamena

Ostrowska, Sabina, và Sabina Ostrowska. Unlock: Listening and Speaking Skills. Cambridge: Cambridge University Press, 2014.

MLA aipamena

Ostrowska, Sabina, và Sabina Ostrowska. Unlock: Listening and Speaking Skills. Cambridge: Cambridge University Press, 2014.