Angraeni, Chelsy, Febri Loska, Lailatul Maghfiroh, and Nuriana (Nino Adhi). “Penelitian Teori Perkembangan Piaget Tahap Operasional Konkret Hukum Kekekalan Volume Anak Usia 11─12 Tahun”. PRISMA, Prosiding Seminar Nasional Matematika 6 (February 28, 2023): 177-180. Accessed May 23, 2024. https://journal.unnes.ac.id/sju/prisma/article/view/66595.