A. Kusumawati, Ishartiwi, and R. R. Handoyo, “Contextual Concrete Media for Improving Subtraction Skills in Elementary Students: Media Konkret Kontekstual untuk Pemahaman Operasi Pengurangan Siswa Sekolah Dasar”, ijins, vol. 26, no. 4, p. 10.21070/ijins.v26i4.1730, Sep. 2025.