text: *[http://www.epa.gov/ttn/chief/ap42/index.html AP 42, Compilation of Air Pollutant Emission Factors] US Environmental Protection Agency
  *[https://web.archive.org/web/20080328084843/http://reports.eea.europa.eu/EMEPCORINAIR5/en/page002.html EMEP/CORIMAIR 2007 Emission Inventory Guidebook].
  *[https://web.archive.org/web/20060904125610/http://files.harc.edu/Projects/AirQuality/Projects/H005.2002/H5FinalReport.pdf Fugitive emissions leaks from ethylene and other chemical plants].