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2. http://www.census.gov/main/www/cen2000.html
3. U.S. Department of Transportation/National Highway Traffic Safety Administration. http://www.nhtsa.dot.gov/people/injury/ems/pub/emtbnsc.pdf
4. U.S. Department of Transportation/National Highway Traffic Safety Administration. http://www.nhtsa.gov/people/injury/ems/EMT-P/disk_1%5B1%5D/index.htm
5. http://www.gemssite.com