Singleton, R. A., & Straits, B. C. (2005). Approaches to social research (4th ed.). Oxford.
Lua i Stíl Chicago (17ú heag.)Singleton, Royce A., agus Bruce C. Straits. Approaches to Social Research. 4th ed. New York: Oxford, 2005.
Lua MLA (9ú heag.)Singleton, Royce A., agus Bruce C. Straits. Approaches to Social Research. 4th ed. Oxford, 2005.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.