Nasution, R. W. (2016). MENINGKATKAN HASIL BELAJAR MATEMATIKA SISWA MELALUI METODE PROBLEM BASED INSTRUCTION DI KELAS VI SD NEGERI NO. 020 BONANDOLOK. JURNAL HANDAYANI PGSD FIP UNIMED, 6(1). https://doi.org/10.24114/jh.v6i1.5045