Harahap, Rika Sari Indah, Derlina Nst, and Zainal Abidin. 2019. “DEVELOPMENT OF PHYSICS LEARNING DEVICE WITH BATAK CULTURE BASED COOPERATIVE LEARNING MODELS”. Jurnal Pendidikan Fisika 8 (1):47-56. https://doi.org/10.22611/jpf.v8i1.13628.