Safitri V, lestari T. 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 [Internet]. 30Jun.2024 [cited 7Jul.2024];5(1):51-7. Available from: http://universe.ppj.unp.ac.id/index.php/universe/article/view/585