Heymann, F. G. (1966). Poland & Czechoslovakia Republic. Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Heymann, Frederick Gotthold. Poland & Czechoslovakia Republic. Englewood Cliffs, N.J: Prentice-Hall, 1966.
Lua MLA (9ú heag.)Heymann, Frederick Gotthold. Poland & Czechoslovakia Republic. Prentice-Hall, 1966.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.