Loka Andari, I.A.K.M., Darsana, I.W. dan Sri Asri, A. 2019. Pengaruh Model Problem Based Learning (PBL) Berbasis Portofolio Terhadap Hasil Belajar IPS. International Journal of Elementary Education. 3, 4 (Okt 2019), 373–380. DOI:https://doi.org/10.23887/ijee.v3i4.21309.