Babbie, E. (1992). The practice of social research (6th ed.). Wadsworth.
Lua i Stíl Chicago (17ú heag.)Babbie, Earl. The Practice of Social Research. 6th ed. California: Wadsworth, 1992.
Lua MLA (9ú heag.)Babbie, Earl. The Practice of Social Research. 6th ed. Wadsworth, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.