Cita APA (7th ed.)

Creswell, J. W. (1994). Research design qualitative & quantitative approaches. Sage.

Cita Chicago (17th ed.)

Creswell, John W. Research Design Qualitative & Quantitative Approaches. London: Sage, 1994.

Cita MLA (9th ed.)

Creswell, John W. Research Design Qualitative & Quantitative Approaches. Sage, 1994.