1. An association between air pollution and mortality in six U.S. cities;Dockery;N Engl J Med,1993
2. Hopke PK. Advances in monitoring methods for airborne particles. 16th international clean air and environment conference, Christchurch, New Zealand; 2002.
3. Variation to the national environment protection (ambient air quality) measure;NEPC,2003
4. Ambient air quality;NEPC,2003
5. WCI, World Coal Institute; www.wci-coal.com, Access date: June 17, 2003.