Wallbank, T. W., & Taylor, A. M. (1949). Civilization: Past & present (Rev ed.). Scott, Foresman.
Lua i Stíl Chicago (17ú heag.)Wallbank, T. Walter, agus Alastair M. Taylor. Civilization: Past & Present. Rev ed. New York: Scott, Foresman, 1949.
Lua MLA (8ú heag.)Wallbank, T. Walter, agus Alastair M. Taylor. Civilization: Past & Present. Rev ed. Scott, Foresman, 1949.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.