Irabien, M. J., J. Soto, M. Rada, A. Mañanes, J. Viguri, and J. Gómez. “An Assessment of Anthropogenic Impact in a Nature Reserve: the Santoña Marshes (Northern Spain)”. Journal of Iberian Geology, vol. 34, vol. 34, no. 2, 2008, pp. 235-42, https://revistas.ucm.es/index.php/JIGE/article/view/JIGE0808220235A.