@article{Calonge Cano_2013, title={Presentación}, url={https://revpubli.unileon.es/ojs/index.php/poligonos/article/view/839}, DOI={10.18002/pol.v0i24.839}, number={24}, journal={Polígonos. Revista de Geografía}, author={Calonge Cano, Guillermo}, year={2013}, month={oct.}, pages={7–9} }