Lundberg, G. A. (1953). Social research: A study methods of gathering data (2nd ed.). Longmans, Green and Co..
Lua i Stíl Chicago (17ú heag.)Lundberg, George A. Social Research: A Study Methods of Gathering Data. 2nd ed. New York, N.Y.: Longmans, Green and Co., 1953.
Lua MLA (8ú heag.)Lundberg, George A. Social Research: A Study Methods of Gathering Data. 2nd ed. Longmans, Green and Co., 1953.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.