Nursyamsiah N. Pengaruh Model Problem Based Introduction (PBI) terhadap Prestasi Belajar IPS Kompetensi Mengenal Jenis-Jenis Usaha dan Kegiatan Ekonomi di Indonesia. fondatia [Internet]. 31Mar.2017 [cited 26Jun.2026];1(1):44-0. Available from: https://ejournal.stitpn.ac.id/index.php/fondatia/article/view/86