Benson, O. E. (1969). Political science laboratory. C. E. Merrill Pub.
Lua i Stíl Chicago (17ú heag.)Benson, Oliver Earl. Political Science Laboratory. Columbus, Ohio: C. E. Merrill Pub, 1969.
Lua MLA (9ú heag.)Benson, Oliver Earl. Political Science Laboratory. C. E. Merrill Pub, 1969.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.