1. El clima;Ascaso,1981
2. Time-dependent atmospheric degradation of building stone in a polluting environment;Attewell;Environmental Geology and Water Sciences,1990
3. Le climat de la Terre;Berger,1992
4. Measurements of erosion on badlands surfaces;Campbell;Zeitschrift für Geomorphologie Supplementband,1974
5. Castan, A., 1999. La fortaleza islámica de Alberuela de Tubo. Diario del Alto Aragón, 19-Septiembre, p. 7.