Villegas Sánchez, R., and J. F. Vale Parapar. 1993. “Evaluation of Hydrophobic Treatments Applied to Stones Used in Andalusian Cathedrals. III.-Accelerated Weathering Test With Polluted Atmosphere”. Materiales De Construcción 43 (232):25-37. https://doi.org/10.3989/mc.1993.v43.i232.665.