Fernández Portela, J. «THE FIELD EXIT AS A TEACHING RESOURCE TO KNOW THE GEOGRAPHICAL SPACE: THE CASE OF THE CITY OF VALLADOLID AND SORIA». Didáctica Geográfica, n.º 18, diciembre de 2017, https://didacticageografica.age-geografia.es/index.php/didacticageografica/article/view/395.