Creswell, J. W., & Plano Clark, V. L. (2011). Designing and conducting mixed methods research (2nd ed.). SAGE Publications.

Creswell, John W., and Vicki L. Plano Clark. Designing and Conducting Mixed Methods Research. 2nd ed. Los Angeles: SAGE Publications, 2011.

Creswell, John W., and Vicki L. Plano Clark. Designing and Conducting Mixed Methods Research. 2nd ed. SAGE Publications, 2011.