(1997). Headway intermediate: Student's book. Oxford: Oxford Univ. Press.
Chicago Style aipamenaHeadway Intermediate: Student's Book. Oxford: Oxford Univ. Press, 1997.
MLA aipamenaHeadway Intermediate: Student's Book. Oxford: Oxford Univ. Press, 1997.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.