1. Sullivan, P., & Porter, J. E. (1993). On theory, practice, and method: Toward a heuristic research methodology for professional writing. Writing in the workplace: New research perspectives, 220–237. p. 233
2. Blakeslee, A. M., & Spilka, R. (2004). The state of research in technical communication. Technical communication quarterly, 13(1), 73–92. p. 85
3. Empirical Research in Technical and Professional Communication: A 5-Year Examination of Research Methods and a Call for Research Sustainability
4. Sullivan, P., & Porter, J. E. (1993). On theory, practice, and method: Toward a heuristic research methodology for professional writing. Writing in the workplace: New research perspectives, 220–237. p. 234
5. Ibid. p. 236