1. U.S. Environmental Protection Agency, Office of Research and Development. Air Quality Criteria for Particulate Matter; EPA-600/P-95/001aF-cF; U.S. Government Printing Office: Washington, DC, 1996.
2. Canadian Environmental Protection Act Federal-Provincial Advisory Committee Working Group on Air Quality Objectives and Guidelines. National Ambient Air Quality Objectives for Ground-Level Ozone, Science Assessment Document; Health Canada and Environment Canada: Ottawa, Ontario, Canada, 1999.
3. Canadian Environmental Protection Act Federal-Provincial Advisory Committee Working Group on Air Quality Objectives and Guidelines. National Ambient Air Quality Objectives for Particulate Matter, Science Assessment Document; Health Canada and Environment Canada: Ottawa, Ontario, Canada, 1999.
4. Guidelines for Air Quality; World Health Organization: Geneva, 1999.
5. Schwartz, J. Particulate Air Pollution and Daily Mortality: A Synthesis; Public Health Rev. 1991-1992, 19, 39-60.