Soars, J., & Soars, L. (1987). Headway: Student's book. Upper-intemediate. Oxford University Press.
Lua i Stíl Chicago (17ú heag.)Soars, John, agus Liz Soars. Headway: Student's Book. Upper-intemediate. Oxford: Oxford University Press, 1987.
Lua MLA (9ú heag.)Soars, John, agus Liz Soars. Headway: Student's Book. Upper-intemediate. Oxford University Press, 1987.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.