Android-based mixed arithmetic operation learning media for mentally retarded students at SLB-C Dharma Rena Ring Putra II. Community Empowerment, [S. l.], v. 7, n. 1, p. 61–66, 2022. DOI: 10.31603/ce.5668. Disponível em: https://journal.unimma.ac.id/ce/article/view/5668. Acesso em: 23 sep. 2026.