SIREGAR, N.; ANDRIANI, A. PENGEMBANGAN BUKU AJAR MATEMATIKA SMP BERBASIS BUDAYA SUMATERA UTARA. Prosiding Seminar Nasional Matematika dan Pendidikan Matematika, [S. l.], v. 4, p. 352–355, 2019. Disponível em: https://conference.upgris.ac.id/index.php/senatik/article/view/77. Acesso em: 3 may. 2024.