Plumb, J. H. (1978). The English heritage. Forum Press.
Lua i Stíl Chicago (17ú heag.)Plumb, John Harold. The English Heritage. St. Louis, Mo: Forum Press, 1978.
Lua MLA (9ú heag.)Plumb, John Harold. The English Heritage. Forum Press, 1978.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.