Norden, R. (1985). Symbols and their meaning. Concordia.
Lua i Stíl Chicago (17ú heag.)Norden, Rudolf. Symbols and Their Meaning. Louis: Concordia, 1985.
Lua MLA (9ú heag.)Norden, Rudolf. Symbols and Their Meaning. Concordia, 1985.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.