Oppenheim, A. N. Questionnaire design and attitude measurement. Heinemann Educational Books.
Cita Chicago Style (17a ed.)Oppenheim, A. N. Questionnaire Design and Attitude Measurement. London: Heinemann Educational Books.
Cita MLA (9a ed.)Oppenheim, A. N. Questionnaire Design and Attitude Measurement. Heinemann Educational Books.
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