Barraclough, G. (1979). Turning Points in World History. Thames and Hudson.
Lua i Stíl Chicago (17ú heag.)Barraclough, Geoffrey. Turning Points in World History. Thames and Hudson, 1979.
Lua MLA (9ú heag.)Barraclough, Geoffrey. Turning Points in World History. Thames and Hudson, 1979.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.