Meléndez, Mónica, Daniel Ballesteros, and Montserrat Jiménez-Sánchez. “Hydrogeology of the Picos De Europa National Park (northern of Spain)”. Boletín Geológico y Minero 130, no. 4 (December 30, 2019): 593–614. Accessed May 3, 2025. https://bgm.revistas.csic.es/index.php/bgm/article/view/149.