Schmidt, S. W., & Shelley, M. C. (1991). American government and politics today. West.
Lua i Stíl Chicago (17ú heag.)Schmidt, Steffen W., agus Mack C. Shelley. American Government and Politics Today. Saint Paul: West, 1991.
Lua MLA (9ú heag.)Schmidt, Steffen W., agus Mack C. Shelley. American Government and Politics Today. West, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.