1. Occupational Safety and Health Administration, Silica, Crystalline. www.osha.gov/dsg/topics/silicacrystalline (accessed 20-03-2020).
2. C. Clerici, M. Patrucco, D. Savoca: “Current problems of risk management of free airborne crystalline silica in mining and excavation activities”, Seminar on “silica pathologies: silicosis, cancer and other diseases”, Trento, 8 May 2001, INAIL Proceedings - Trentino Regional Directorate, pp. 93-110. (in Italian).
3. S. Francese, M. Patrucco, G. Scioldo: “Workers exposure to airborne particulates in opencast and underground mining operations: a database approach for risk assessment and management”, Data Mining III Conference 2002, Bologna, 25-27 September 2002, Proceedings, pp. 829-838, WIT Press, ISBN 1-85312-925-9, ISSN 1470-6326.
4. ISO7708:1995. Air quality— Particle size fraction definitions for health-related sampling.
5. EN 481:1993. Workplace atmospheres - Size fraction definitions for measurement of airborne particles.