Gaya APA

W.Creswell, J. (2009). Research Design: Qualitative, Quantitative,and Mixed Methods Approanches (3rd ed c.2). London: SAGE.

Gaya MLA

W.Creswell, John. "Research Design: Qualitative, Quantitative,and Mixed Methods Approanches". 3rd ed c.2 London: SAGE, 2009. Text.