Soto Vera, Anahí Concepción, and David Velázquez Seiferheld. “Ramón Indalecio Cardozo (1876-1943). Pioneer of the Paraguayan Active School”. Revista Historia de la Educación Latinoamericana 21, no. 32 (April 28, 2019): 15–34. Accessed March 29, 2024. https://revistas.uptc.edu.co/index.php/historia_educacion_latinamerican/article/view/9381.