Singer, L. (1980). Sociology: A students introduction. University Press of America.
Lua i Stíl Chicago (17ú heag.)Singer, Lester. Sociology: A Students Introduction. University Press of America, 1980.
Lua MLA (9ú heag.)Singer, Lester. Sociology: A Students Introduction. University Press of America, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.