Gaya APA

Creswell, J, W. (2009). Research design: qualitative, quantitative, and mixed methods approaches (3rd ed.). California: Sage Publications.

Gaya MLA

Creswell, John, W.. "Research design: qualitative, quantitative, and mixed methods approaches". 3rd ed. California: Sage Publications, 2009. eBook Kesehatan Masyarakat.