BABBIE. (1973). Survey Research Methods Babbie. Wadsworth.
Lua i Stíl Chicago (17ú heag.)BABBIE. Survey Research Methods Babbie. Wadsworth, 1973.
Lua MLA (8ú heag.)BABBIE. Survey Research Methods Babbie. Wadsworth, 1973.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.