@article{Graue, B.2013, author = "B. Graue and S. Siegesmund and P. Oyhantcabal and R. Naumann and T. Licha and K. Simon", doi = "10.1007/s12665-012-2161-6", issn = "1866-6280", journal = "Environmental Earth Sciences", keywords = "Cologne cathedral; Xanten cathedral; Altenberg cathedral; Weathering crusts; Pollution impact; Stone decay processes; Drachenfels trachyte", number = "4", pages = "1095-1124", publisher = "Springer-Verlag", title = "{T}he effect of air pollution on stone decay: the decay of the {D}rachenfels trachyte in industrial, urban, and rural environments—a case study of the {C}ologne, {A}ltenberg and {X}anten cathed", url = "http://dx.doi.org/10.1007/s12665-012-2161-6", volume = "69", year = "2013", }