Teggart, F. J. (1949). The idea of progress: A collection of readings (rev. ed.). University of California Press.
Lua i Stíl Chicago (17ú heag.)Teggart, Frederick John. The Idea of Progress: A Collection of Readings. rev. ed. Berkeley: University of California Press, 1949.
Lua MLA (9ú heag.)Teggart, Frederick John. The Idea of Progress: A Collection of Readings. rev. ed. University of California Press, 1949.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.