^Smith, K. (March 1983). "Quantitative versus Qualitative Research: An Attempt to Clarify the Issue". Educational Researcher. 12 (3): 6–13. doi:10.3102/0013189x012003006. JSTOR1175144.
^Newman, Benz, I., C. (1998). Qualitative-Quantitative Research Methodology: Exploring the Interactive Continuum. Southern Illinois University. pp. 9–10.