Nichols, P. (1991). Social survey methods: A fieldguide for development workers. Oxfam Publications.
Lua i Stíl Chicago (17ú heag.)Nichols, Paul. Social Survey Methods: A Fieldguide for Development Workers. Oxford: Oxfam Publications, 1991.
Lua MLA (8ú heag.)Nichols, Paul. Social Survey Methods: A Fieldguide for Development Workers. Oxfam Publications, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.