Donnelly, J. P., & Trochim, W. M. K. (2005). Research methods: The concise knowledge base workbook. Atomic Dog Pub..

Donnelly, James P., and William M. K. Trochim. Research Methods: The Concise Knowledge Base Workbook. Cincinnati, Ohio: Atomic Dog Pub., 2005.

Donnelly, James P., and William M. K. Trochim. Research Methods: The Concise Knowledge Base Workbook. Atomic Dog Pub., 2005.