West, W. M. (1923). The story of modern progress: With a preliminary survey of earlier progress (Rev. ed.). Allyn and Bacon.
Lua i Stíl Chicago (17ú heag.)West, Willis M. The Story of Modern Progress: With a Preliminary Survey of Earlier Progress. Rev. ed. Boston ; New York [etc.]: Allyn and Bacon, 1923.
Lua MLA (8ú heag.)West, Willis M. The Story of Modern Progress: With a Preliminary Survey of Earlier Progress. Rev. ed. Allyn and Bacon, 1923.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.