ROBERTS, J. (1967). Europe 1880-1945. Longmans.
Lua i Stíl Chicago (17ú heag.)ROBERTS, John. Europe 1880-1945. London: Longmans, 1967.
Lua MLA (9ú heag.)ROBERTS, John. Europe 1880-1945. Longmans, 1967.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.