Black, M. (2006). Objective IELTS: Advanced teacher'sbook. Cambridge: Cambridge University Press.
Chicago Style aipamenaBlack, Michael. Objective IELTS: Advanced Teacher'sbook. Cambridge: Cambridge University Press, 2006.
MLA aipamenaBlack, Michael. Objective IELTS: Advanced Teacher'sbook. Cambridge: Cambridge University Press, 2006.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.