Babbie, E. R. (1975). The practice of social research. Wodsworth Publ.
Lua i Stíl Chicago (17ú heag.)Babbie, Earl R. The Practice of Social Research. Wodsworth Publ, 1975.
Lua MLA (8ú heag.)Babbie, Earl R. The Practice of Social Research. Wodsworth Publ, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.