1. Ball, D. L., Thames, M. H., & Phelps, G. (2008). Content knowledge for teaching: What makes it special? Journal of Teacher Education, 59(5), 389–407.
2. Ball, D. L., Hill, H. C., Bass, H. (2005). Who knows mathematics well enough to teach third grade, and how can we decide? American Educator, 30(3), 14–17, 20–22, 43–46.
3. Burch, P. (2009). Hidden markets: The new education privatization. Routledge.
4. Creswell, J. W., & Poth, C. N. (2018). Qualitative inquiry and research design: Choosing among five approaches (4th ed.). Sage Publications.
5. Darling-Hammond, L. (1996). The right to learn and the advancement of teaching: Research, policy, and practice for democratic education. Educational Researcher, 25(6), 5–17.