Nisbet, R. A. (1994). History of the idea of progress. New Brunswick.
Lua i Stíl Chicago (17ú heag.)Nisbet, Robert A. History of the Idea of Progress. New Brunswick ; London: New Brunswick, 1994.
Lua MLA (8ú heag.)Nisbet, Robert A. History of the Idea of Progress. New Brunswick, 1994.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.