O'Connor, J. (1977). Better English Pronounciation. Cambridge University Press.
Chicago Style aipamenaO'Connor, J.D. Better English Pronounciation. London: Cambridge University Press, 1977.
MLA aipamenaO'Connor, J.D. Better English Pronounciation. Cambridge University Press, 1977.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.