Hafizh, Doejan Grada, and Agus Suwahyono. “Problem-Based Learning Model in Arts and Culture Subjects Vocal Arts Materials for Grade 9f at SMPN 3 Kutorejo”. Solah, vol. 11, no. 1, Dec. 2025, pp. 66-86, https://ejournal.unesa.ac.id/index.php/solah/article/view/73477.