Hornby, A. Oxford progressive english for adult Learners. Oxford University Press.
Lua i Stíl Chicago (17ú heag.)Hornby, A.S. Oxford Progressive English for Adult Learners. London: Oxford University Press.
Lua MLA (9ú heag.)Hornby, A.S. Oxford Progressive English for Adult Learners. Oxford University Press.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.