http://www.epa.gov/air/aqtrnd03/dl_graph.html
Graphs and tables from the EPA’s National Air Quality and Emissions Trends Report (2003). Comparison of 1970 and 2002 Emissions.
http://www.epa.gov/air/aqtrnd03/dl_graph.html
Graphs and tables from the EPA’s National Air Quality and Emissions Trends Report (2003). Comparison of 1970 and 2002 Emissions.
