Michels, R., & De Grazia, A. (1965). First lectures in political sociology. Harper.
Lua i Stíl Chicago (17ú heag.)Michels, Robert, agus Alfred De Grazia. First Lectures in Political Sociology. New York: Harper, 1965.
Lua MLA (9ú heag.)Michels, Robert, agus Alfred De Grazia. First Lectures in Political Sociology. Harper, 1965.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.