Arliansyah Maulana 2024. Teori Perkembangan Kognitif Piaget Pada Tahap Operasional Formal. Al-Ahnaf: Journal of Islamic Education, Learning and Religious Studies . 1, 1 (Jul. 2024), 12–21. DOI:https://doi.org/10.61166/ahnaf.v1i1.7.