Cooper, B., & Voegelin, E. (1999). Eric Voegelin and the foundations of modern political science. University of Missouri Press.
Lua i Stíl Chicago (17ú heag.)Cooper, Barry, agus Eric Voegelin. Eric Voegelin and the Foundations of Modern Political Science. Columbia: University of Missouri Press, 1999.
Lua MLA (9ú heag.)Cooper, Barry, agus Eric Voegelin. Eric Voegelin and the Foundations of Modern Political Science. University of Missouri Press, 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.