Clark, C. M. (2006). Iron kingdom: The rise and downfall of Prussia, 1600-1947. Belknap Press of Harvard University Press.
Lua i Stíl Chicago (17ú heag.)Clark, Christopher M. Iron Kingdom: The Rise and Downfall of Prussia, 1600-1947. Cambridge, Mass.: Belknap Press of Harvard University Press, 2006.
Lua MLA (8ú heag.)Clark, Christopher M. Iron Kingdom: The Rise and Downfall of Prussia, 1600-1947. Belknap Press of Harvard University Press, 2006.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.