A Validity of E-LKPD Based on Problem Based Learning for Improve Critical Thinking Skill. Indonesian Journal of Education Research (IJoER), [S. l.], v. 5, n. 6, p. 277–285, 2024. DOI: 10.37251/ijoer.v5i6.1244. Disponível em: https://cahaya-ic.com/index.php/IJoER/article/view/1244. Acesso em: 15 jun. 2026.