MUTMAINAH, S.; SULIANI, M. An Ethnographic Study of Abacus Use Among Visually Impaired Individuals in Solving Addition and Subtraction Problems. Jurnal Pendidikan Matematika Universitas Lampung, [S. l.], v. 14, n. 2, p. 147–156, 2026. DOI: 10.23960/mtk/v14i2.pp147-156. Disponível em: https://jurnal.pbs.fkip.unila.ac.id/index.php/jpm/article/view/1522. Acesso em: 17 jul. 2026.