Zul Ikhsan, and Syarifuddin. “Analisis Kesalahan Prosedural Siswa Pada Operasi Hitung Barisan Dan Deret Melalui Problem Based Learning”. ARMADA : Jurnal Penelitian Multidisiplin, vol. 4, no. 6, June 2026, pp. 1846-55, doi:10.55681/armada.v4i6.2630.