1. Orenstein AJ. Proceedings of the 1959 pneumoconiosis conference, Johannesburg. Churchill, London, UK; 1960.
2. BMRC. British Medical Research Council Report, UK; 1952.
3. International Standards Organization (ISO), Air quality: particle size fraction definitions for health-related sampling. Geneva, Switzerland: International Organization for Standardization. ISO 7708, Geneva; 1995.
4. Proposed international conventions for particle size-selective sampling;Soderholm;Ann Occup Hyg,1989
5. Why change ACGIH’s definition of respirable dust;Soderholm;Appl Occup Environ Hyg,1991