Sanna, Laura, et al. “A Geomorphological and Speleological Approach in the Study of Hydrogeology of Gypsum Karst of Sorbas (SE Spain)”. Geografia Fisica E Dinamica Quaternaria, vol. 35, no. 2, Dec. 2012, pp. 153-66, https://doi.org/10.4461/GFDQ.2012.35.14.