Lua APA (7ú heag.)
Langford, J. W. (2011). The gap is not a theory! Xlibris Corp..
Lua i Stíl Chicago (17ú heag.)
Langford, Jack W. The Gap Is Not a Theory! United States: Xlibris Corp., 2011.
Lua MLA (9ú heag.)
Langford, Jack W. The Gap Is Not a Theory! Xlibris Corp., 2011.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.