Torres Aguilar M. UNIVERSITY EXTENSION AND POPULAR UNIVERSITIES: THE FREE EDUCATION MODEL AT THE UNIVERSIDAD POPULAR MEXICANA (1912-1920). Rev. hist.edu.latinoam [Internet]. 2011 Jan. 28 [cited 2024 Jun. 30];(12). Available from: https://revistas.uptc.edu.co/index.php/historia_educacion_latinamerican/article/view/1521