TUMANGGOR, Riossally Marselina; SITUMEANG, Sarinaiba; SINAGA, Henokh Granto; ASNIDA, Asnida; LUMBANTOBING, Nanny Natania; NABABAN, Tulus; LAIA, Ridana; PANE, Januaris. Efektivitas Layanan Bimbingan Belajar Untuk Meningkatkan Konsentrasi Belajar Siswa SMP Negeri 1 Tapian Nauli. Indonesia Berdaya, [S. l.], v. 3, n. 2, p. 331–338, 2022. DOI: 10.47679/ib.2022226. Disponível em: https://ukinstitute.org/journals/ib/article/view/226. Acesso em: 8 jul. 2026.