Langan, J. (1988). English skills with readings (3rd ed.). McGraw hill.
Lua i Stíl Chicago (17ú heag.)Langan, John. English Skills with Readings. 3rd ed. New York: McGraw hill, 1988.
Lua MLA (9ú heag.)Langan, John. English Skills with Readings. 3rd ed. McGraw hill, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.