يونس محمود س. Effect of using feed back in Problem solution of Balance concept to students in elementary school. College of Basic Education Research Journal, [S. l.], v. 2, n. 3, p. 51–83, 2006. Disponível em: https://stats.uomosul.edu.iq/index.php/berj/article/view/38969. Acesso em: 26 oct. 2025.