Langan, J. (2002). English skills with readings (5th ed.). McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Langan, John. English Skills with Readings. 5th ed. Boston: McGraw-Hill, 2002.
Lua MLA (8ú heag.)Langan, John. English Skills with Readings. 5th ed. McGraw-Hill, 2002.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.