NEED ANALYSIS OF DIGITAL TEACHING MATERIALS WITH STEM APPROACH AND FLIP BOOK-FORMED TO IMPROVE SELF-REGULATED SKILLS FOR PRE-SERVICE TEACHERS. SPEKTRA [Internet]. 2024 Sep. 30 [cited 2025 Nov. 26];10(2):185-9. Available from: https://ojs.unsiq.ac.id/index.php/spektra/article/view/7732