Halecki, O. (1957). Poland. Published for the Mid-European Studies Center of the Free Europe Committee by F. A. Praeger.
Lua i Stíl Chicago (17ú heag.)Halecki, Oskar. Poland. New York: Published for the Mid-European Studies Center of the Free Europe Committee by F. A. Praeger, 1957.
Lua MLA (9ú heag.)Halecki, Oskar. Poland. Published for the Mid-European Studies Center of the Free Europe Committee by F. A. Praeger, 1957.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.