Punch, K. (2005). Introduction to social research: Quantitative and qualitative approaches (2nd Ed.). SAGE Publications.

Punch, Keith. Introduction to Social Research: Quantitative and Qualitative Approaches. 2nd Ed. London ; Thousand Oaks, Calif.: SAGE Publications, 2005.

Punch, Keith. Introduction to Social Research: Quantitative and Qualitative Approaches. 2nd Ed. SAGE Publications, 2005.