*[https://web.archive.org/web/20080405110339/http://www.ipcc-nggip.iges.or.jp/public/2006gl/index.htm 2006 IPCC Guidelines for National Greenhouse Gas Inventories ]
*[https://web.archive.org/web/20080321094829/http://www.ipcc-nggip.iges.or.jp/public/gl/invs6.htm Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories (reference manual)].
*[http://www.ipcc-nggip.iges.or.jp/EFDB/main.php IPCC Emission Factor Database]
*[http://www.ec.gc.ca/pdb/ghg/inventory_report/2005_report/tdm-toc_eng.cfm National Inventory Report: Greenhouse Gas Sources and Sinks in Canada].
* [https://web.archive.org/web/20100707144526/http://www.naei.org.uk/emissions/index.php United Kingdom's emission factor database].