The Effect of the Problem Based Learning on EFL Learners’ Achievement. Journal Of Educational and Psychological Researches, [S. l.], v. 11, n. 43, p. 270–287, 2014. Disponível em: https://www.jperc.uobaghdad.edu.iq/index.php/jperc/article/view/467. Acesso em: 5 jul. 2025.