Brecht, A. (1959). Political theory: The foundations of twentieth century political thought. Princeton University Press.
Lua i Stíl Chicago (17ú heag.)Brecht, Arnold. Political Theory: The Foundations of Twentieth Century Political Thought. Princeton, N.J: Princeton University Press, 1959.
Lua MLA (9ú heag.)Brecht, Arnold. Political Theory: The Foundations of Twentieth Century Political Thought. Princeton University Press, 1959.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.