Ramadhani, Oktamia, et al. “Trend Riset Problem-Based Learning Dalam Pembelajaran Alat Optik: Analisis Bibliometrik Dengan VOSviewer”. Studies in Physics Teaching and Learning, vol. 1, no. 1, Sept. 2025, pp. 31-40, https://journal.unesa.ac.id/index.php/sptl/article/view/45325.