Professional and Technical Communication is a relatively new field, with a fairly small set of journals that are central to the field. According to studies by Smith and Lowry et al. these are the core PTC journals: The Journal of Business and Technical Communication, IEEE Transactions on Professional Communication, The Journal of Technical Writing and Communication, Technical Communication, and Technical Communication Quarterly. Smith used citation analysis to come to that conclusion. Lowry et al. used the opinions of experts. Neither method is authoritative, but if I had to pick a journal to read to get the best of PTC, it would be one of those. So this is useful to know, but it doesn't get at specific secondary sources central to the field. Journals are one thing, but which books and articles stand out as particularly widely read? I took those five journals and counted citations to primary sources in them between approximately 2005 and 2015. Because of the way that Web of Science and Scopus parse out data files (and limitations in my current access), some of the journals extend to 2004 while some coverage doesn't start until 2009. It's an uneven data set, which I'll being fixing in the future. Still this exercise is good for a rough estimate of what research is seeing play in the field. The ten most cited sources in the field are:

1. 30 citations. Spinuzzi, C. (2003). Tracing genres through organizations: A sociocultural approach to information design:Cambridge, MA: MIT Press.
2. 24 citations. Miller, C.R. (1984). Genre as social action. Quarterly Journal of Speech, 70(2), 151-167.
3. 17 citations. Johnson-Eilola, J. (1996). Relocating the value of work: Technical Communication in a post-industrial age. Technical Communication Quarterly, 5(3), 245-270.
4. 16 citations. Russell, D. R. (1997). Rethinking genre in school and society: An activity theory analysis. Written Communication, 14(4), 504-554.
5. 15 citations. Miller, C.R. (1979). A humanistic rationale for technical writing. College English, 40(6), 610-617.
6. 14 citations. Bazerman, C. (1988). Shaping written knowledge: The genre and activity of the experimental article in science. Madison: University of Wisconsin Press.
7. 13 citations. Farkas, D. K. (1999). The logical and rhetorical construction of procedural discourse. Technical Communication, 46(1), 42-54.
8. 13 citations. Lave, J., & Wenger, E. (1991). Situated learning: Legitimate peripheral participation. Cambridge: Cambridge University Press.
9. 12 citations. Hart-Davidson, W. (2001). On writing, technical communication, and information technology: The core competencies of technical communication. Technical Communication, 48(2), 145–155.
10. 12 citations. Starke-Meyerring, D. (2005). Meeting the challenges of globalization: A framework for global literacies in professional communication programs. Journal of Business and Technical Communication, 19(4), 468–499.

Those numbers might seem low, but keep in mind that is only for the five core journals in PTC for the last 10 years. So, for example, Google Scholar suggests that the Starke-Meyerring article has 64 citations in the total 2005-2015 Google Scholar universe. My count is only noting references to that piece from within the five journals. So in all, about 20% of the Scholar citations are coming from the PTC journal set. Since its interesting to know those percentages, I figured them for the whole set. Again, I limited the Googler Citations to 2005-2015 because that's the time period of my corpus.

1. 30/294 = 10%. Spinuzzi, C. (2003). Tracing genres through organizations: A sociocultural approach to information design:Cambridge, MA: MIT Press.
2. 24/1940 = 1%. Miller, C.R. (1984). Genre as social action. Quarterly Journal of Speech, 70(2), 151-167.
3. 17/92 = 18%. Johnson-Eilola, J. (1996). Relocating the value of work: Technical Communication in a post-industrial age. Technical Communication Quarterly, 5(3), 245-270.
4. 16/470 = 3%. Russell, D. R. (1997). Rethinking genre in school and society: An activity theory analysis. Written Communication, 14(4), 504-554.
5. 15/142 = 11%. Miller, C.R. (1979). A humanistic rationale for technical writing. College English, 40(6), 610-617.
6. 14/1380 = 1%. Bazerman, C. (1988). Shaping written knowledge: The genre and activity of the experimental article in science. Madison: University of Wisconsin Press.
7. 13/54 = 24%. Farkas, D. K. (1999). The logical and rhetorical construction of procedural discourse. Technical Communication, 46(1), 42-54.
8. 13/32900 = less than a hundredth of 1%. Lave, J., & Wenger, E. (1991). Situated learning: Legitimate peripheral participation. Cambridge: Cambridge University Press.
9. 12/64 = 19%. Hart-Davidson, W. (2001). On writing, technical communication, and information technology: The core competencies of technical communication. Technical Communication, 48(2), 145–155.
10. 12/66 = 18%. Starke-Meyerring, D. (2005). Meeting the challenges of globalization: A framework for global literacies in professional communication programs. Journal of Business and Technical Communication, 19(4), 468–499.

Note that when that percentage starts dropping below 10%, the source is more likely to be an import that's not specifically about PTC. The higher percentages are articles that are field specific. While I was at it, I calculated the most cited authors in my corpus, too. This counted citations across publications. This is no surprise.

1. C. Spinuzzi: 224 citations
2. C. Bazerman: 160 citations
3. B. Latour: 135 citations
4. C. Miller: 127 citations
5. E. Tebeaux: 126 citations
6. A. Freedman: 122 citations
7. G. Hofstede 114 citations
8. R.L. Daft: 105 citations
9. J. Yates: 103 citations
10. J. Johnson-Eilola: 102 citations

If I were learning PTC as a field, these are the sources and authors that I would read to get up to speed and increase the likelihood that I could have a conversation with a colleague in the field.