Oppenheim, A. N. (1966). Questionnaire design and attitude measurement. Heinemann.
Lua i Stíl Chicago (17ú heag.)Oppenheim, A. N. Questionnaire Design and Attitude Measurement. London: Heinemann, 1966.
Lua MLA (8ú heag.)Oppenheim, A. N. Questionnaire Design and Attitude Measurement. Heinemann, 1966.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.