Norton, P. (2003). Peter Norton's essential concepts (5th ed.). Glencoe/McGraw-Hill.
Lua i Stíl Chicago (17ú heag.)Norton, Peter. Peter Norton's Essential Concepts. 5th ed. New York: Glencoe/McGraw-Hill, 2003.
Lua MLA (8ú heag.)Norton, Peter. Peter Norton's Essential Concepts. 5th ed. Glencoe/McGraw-Hill, 2003.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.