Ferman, G. S., & Levin, J. (1975). Social Science Research: A handbook for students. Schenkman.
Lua i Stíl Chicago (17ú heag.)Ferman, Gerald S., agus Jack Levin. Social Science Research: A Handbook for Students. Massachusetts: Schenkman, 1975.
Lua MLA (9ú heag.)Ferman, Gerald S., agus Jack Levin. Social Science Research: A Handbook for Students. Schenkman, 1975.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.