INTEGRATION OF EDUCATION FOR SUSTAINABLE DEVELOPMENT INTO SECONDARY SCHOOL CURRICULA: A REVIEW OF PEDAGOGICAL APPROACHES, TEACHER PREPAREDNESS, STUDENT ENVIRONMENTAL AWARENESS, BEHAVIORAL CHANGE OUTCOMES, AND CROSS-NATIONAL POLICY FRAMEWORKS. IJSSB. 2026;4(5):550-573. Accessed May 13, 2026. https://ijssbulletin.com/index.php/IJSSB/article/view/2285