Creswell, J. W. (2014). Research design: Qualitative, quantitative, and mixed methods approaches (4a. ed.). Sage.
Chicago-viite (17. p.)Creswell, John W. Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. 4a. ed. Thousand Oaks: Sage, 2014.
MLA-viite (9. p.)Creswell, John W. Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. 4a. ed. Sage, 2014.
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