Nugrahaningrum, Redita Kikan, et al. “Analisis Bibliometrik: Pengembangan Konseptual Dan Keterampilan Abad Ke-21 Melalui Physics Problem-Based Learning”. Epistemic: Scientific Thinking and Literacy , vol. 1, no. 1, Aug. 2025, pp. 20-29, doi:10.58706/epistemic.v1n1.p20-29.