2024. THE EFFECT PROBLEM BASED LEARNING ASSISTED BY QUESTION CARDS ON CRITICAL THINGKING SKILLS ON ADDITIVE AND ADDICTIVE SUBSTANCES FOR VIII GRADE STUDENTS OF SMPN 38 PADANG. Universe. 5, 1 (Jun. 2024), 51–57. DOI:https://doi.org/10.24036/universe.v5i1.585.