1. Abbott, J., 2005. Primary nitrogen dioxide emissions from road traffic: analysis of monitoring data. AEA Technology, National Environmental Technology Centre, Report AEAT-1925. http://www.airquality.co.uk/archive/reports/cat05/0703151041_primno2v3.pdf.
2. Airbase, 2006. http://air-climate.eionet.europa.eu/databases/airbase/.
3. Air Quality Expert Group (AQEG), 2007. Primary NO2 in the United Kingdom http://www.defra.gov.uk/environment/airquality/publications/primaryno2-trends/index.htm.
4. Central Data Repository (CDR), 2006. http://cdr.eionet.europa.eu/.
5. Evidence of an increasing NO2/NOx emissions ratio from road traffic emissions;Carslaw;Atmospheric Environment,2005