García Hernández, Ernesto, and Joaquín Bosques Sendra. “Bases De Datos cartográficas De Cobertura Global Accesibles on-Line”. GeoFocus. International Review of Geographical Information Science and Technology, no. 1 (December 31, 2001): 5–10. Accessed May 20, 2025. https://www.geofocus.org/index.php/geofocus/article/view/318.