Nopriana, T., Asnawati, S., Herman, T., Martadiputra, B. A. P., & Dejarlo, J. O. (2024). Investigating ontogenic and didactical obstacles faced by vocational high school students in solving counting rules problems. International Journal of Didactic Mathematics in Distance Education, 1(2), 102–114. https://doi.org/10.33830/ijdmde.v1i2.9524