Villar, Antonio. “Education and Cognitive Skills in the Spanish Adult Population. Inter-Generational Comparison of Mathematical Knowledge from the PIAAC Data”. Advances in Social Sciences Research Journal 1, no. 1 (February 3, 2014): 72–88. Accessed September 29, 2024. http://116.203.177.230/index.php/ASSRJ/article/view/49.