1. Particle Emissions from a Small Two-Stroke Engine: Effects of Fuel, Lubricating Oil, and Exhaust Aftertreatment on Particle Characteristics
2. AXA. (2008). SMEs responsible for 110 million tonnes of carbon emissions each year. Retrieved from: http://newsroom.axa.co.uk/media-releases/2008/smes-responsible-for-110-million-tonnes-of-carbon-emissions-each-year/.
3. Biomass Energy Centre. (2011). Chipping – What can be chipped? Retrieved from: http://www.biomassenergycentre.org.uk/portal/page?_pageid = 75,17827&_dad = portal&_schema = PORTAL.
4. BioRegional Development Group. (2008). Biomass fuels for London: Wood fuel demand and supply chains. London Energy Partnership. Retreived from: http://www.lep.org.uk/uploads/LEP%20Biomass%20for%20London%20Wood%20Fuel%20Supply%20Chains%20(inc%20ISBN)%20Jan%202009%20FINAL.pdf.
5. Bishop, R. (2008). Safety impacts of speed limiter device installations on commercial trucks and buses. Washington, DC: Transportation Research Board. Retrieved from: http://onlinepubs.trb.org/onlinepubs/ctbssp/ctbssp_syn_16.pdf.