Alkiftiyah, Mariyah, et al. “Problem Based Leearning Untuk Meningkatkan Keterampilan Bertanya Problem Based Learning to Improve Questioning Skills”. Jurnal Pendidikan Tambusai, vol. 8, no. 2, June 2024, pp. 21351-60, https://jptam.org/index.php/jptam/article/view/16052.