Yurniwati, Yurniwati, and Cecep Kustandi. “Determination and Comparison Pedagogical Content Knowledge of Pre-Service and In-Service Elementary School Teachers in Mathematics”. Journal of Higher Education Theory and Practice 22, no. 4 (May 11, 2022). Accessed July 3, 2024. https://articlegateway.com/index.php/JHETP/article/view/5161.