1. Comité Européen de Normalisation (CEN), Workplace atmospheres: size fraction definitions for measurement of airborne particles in the workplace, European Standard EN 481, CEN, Brussels, Belgium, 1993
2. International Standards Organization (ISO), Air quality–particle size fraction definitions for health-related sampling, ISO Standard ISO 7708, ISO, Geneva, 1995
3. American Conference of Governmental Industrial Hygienists (ACGIH), Particle size-selective sampling for particulate air contaminants, ed. J. H. Vincent, ACGIH, Cincinnati, OH, 1999
4. Aerosol Instrumentation in Occupational Hygiene: An Historical Perspective