Gaya APA
Creswell, J, W. (2009).
Research Design: Qualitative, Quantitative, and MIxed Methods Approazhes (Edisi Ketiga).
California:
SAGE Publications, Inc..
Gaya MLA
Creswell, John, W.
"Research Design: Qualitative, Quantitative, and MIxed Methods Approazhes".
Edisi Ketiga
California:
SAGE Publications, Inc.,
2009.
Texts.