1. D. Camuffo, in: T. Schneider (Ed.), Acidification and its Policy Implication, Elsevier, Amsterdam, 1986, p. 189.
2. Contribution of atmospheric deposition to the formation of damage layers
3. Chemical Analysis of Thin Black Layers on Building Stone
4. R.A. Livingston, in: R.G.M. Webster (Ed.), Stone Cleaning and the Nature, Soiling and Decay Mechanisms of Stone, Proceedings of the International Conference, Donhead, London, 1992, p. 166.
5. Th. Skoulikidis, P. Papakonstantinou, in: R.G.M. Webster (Ed.), Stone Cleaning and the Nature, Soiling and Decay Mechanisms of Stone, Proceedings of the International Conference, Donhead, London, 1992, p. 155.