Student worksheet oriented on science, technology, engineering, and mathematics (STEM) with PjBL model on acid base matter by using natural product. J.Pendidik.Kim [Internet]. 2021 Apr. 1 [cited 2026 Mar. 23];13(1):22-37. Available from: https://jurnal.unimed.ac.id/2012/index.php/jpk/article/view/24141