Esparó, G., Torrente, M., Fernández-ballart, J. D. y Canals, J. (2004): «Psychological problems and associated factors at 6 years of age: Differences between sexes»., The Spanish Journal of Psychology, 7(1), pp. 53–62. Disponible en: https://revistas.ucm.es/index.php/SJOP/article/view/SJOP0404120053A (Accedido: 5 diciembre 2025).