Plumb, J. H. (1964). Crisis in the humanities. Penguin Books.
Lua i Stíl Chicago (17ú heag.)Plumb, J. H. Crisis in the Humanities. Baltimore: Penguin Books, 1964.
Lua MLA (8ú heag.)Plumb, J. H. Crisis in the Humanities. Penguin Books, 1964.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.