Littlejohn, A. (2001). Cambridge english worldwide. Cambridge: Cambridge University Press.
Chicago Style aipamenaLittlejohn, Andrew. Cambridge English Worldwide. Cambridge: Cambridge University Press, 2001.
MLA aipamenaLittlejohn, Andrew. Cambridge English Worldwide. Cambridge: Cambridge University Press, 2001.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.