Creswell, J. W. (2009). Research design: Qualitative, quantitative, and mixed methods approaches (3rd ed.). Sage Publications.
Dyfyniad Arddull ChicagoCreswell, John W. Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. 3rd ed. Thousand Oaks, Calif.: Sage Publications, 2009.
Dyfyniad MLACreswell, John W. Research Design: Qualitative, Quantitative, and Mixed Methods Approaches. 3rd ed. Sage Publications, 2009.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.