Butterfield, K. L. (1908). Chapters in rural progress. University of Chicago Press.
Lua i Stíl Chicago (17ú heag.)Butterfield, Kenyon L. Chapters in Rural Progress. Chicago: University of Chicago Press, 1908.
Lua MLA (8ú heag.)Butterfield, Kenyon L. Chapters in Rural Progress. University of Chicago Press, 1908.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.