Gaya APA
Creswell, J, W., Creswell, J, D. (2018).
Research Design Qualitative, Quantitative, and Mixed Methods Approaches .
California:
Sage Publications.
Gaya MLA
Creswell, John, W.., Creswell, J., David.
"Research Design Qualitative, Quantitative, and Mixed Methods Approaches".
California:
Sage Publications,
2018.
Computer File.