Roberts, J. M. (1989). Europe, 1880-1945 (2nd ed.). Longman.
Lua i Stíl Chicago (17ú heag.)Roberts, J. M. Europe, 1880-1945. 2nd ed. London: Longman, 1989.
Lua MLA (9ú heag.)Roberts, J. M. Europe, 1880-1945. 2nd ed. Longman, 1989.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.