Martín Patino, María Teresa, Fernando Madruga, and Julio Saavedra. “Selective Sandstone Deterioration in the Cathedrals of Salamanca, Textural Anisotropy As a Cause”. Materiales de Construcción 44, no. 235 (September 30, 1994): 5–14. Accessed April 26, 2024. https://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/578.