1. Pollutant effects on stone monuments;Lal Gauri;Environmental Science and Technology,1981
2. Chemical analysis of thin black layers on building stone;Nord;Studies in Conservation,1993
3. Application of laser radiation to the cleaning of statuary;Lazzarini;Bulletin of AIC,1973
4. Surface morphology of laser cleaned stone;Asmus;Lithoclastia,1976
5. A comparative study of the laser cleaning of limestone;Cooper,1992