1. B. Mühlethaler, J. Thissen: Stud. Conserv. 14, 47 (1969)
2. E. Ciliberto, I. Fragalà, G. Pennisi, G. Spoto: Sci. Technol. Cult. Heritage 3, 163 (1994)
3. F. Baldini, G. Botticelli, C. Danti, M. Matteini, A. Moles: Case Studies in the Conservation of Stone and Wall Paintings (IIC, London, UK 1986)
4. E. Ciliberto, C. Altavilla: LaChim. L’Ind. 7, 84 (2002)
5. D.C. Frost, C.A. McDowell, I.S. Woolsey: Chem. Phys. Lett. 17, 320 (1972)