U. Eichhorst, “Adapting Urban Transport to Climate Change,” In: GTZ, Ed., Sustainable Transport: A Sourcebook for Policy Makers in Developing Cities, Germany, 2009. http://www.sutp.org/index.php?option=com_docman&task=cat_view&gid=29&Itemid=54&lang=en
 Environmental Protection Agency, “Inventory of US Greenhouse Gas Emissions and Sinks,” 1990-2001. http://yosemite.epa.gov/oar/globalwarming.nsf/UniqueKeyLookup/LHOD5MJQ6G/$File/2003-final-inventory.pdf, April 15, 2003. Estimates are presented in units of terra-grams of carbon dioxide equivalents (Tg CO2 Eq.), which weight each gas (e.g., CO2 and NOx) by its Global Warming Potential, or GWP, value
 Carbon footprint. http://www.2celsius.org/new/2011/01/03/aviation-industrys-attempt-at-flying-green/
 ATAG, “ATAG and GARDN Sign Agreement to Promote Environmental Research in Aviation,” 2012. http://www.newswire.ca/en/story/943107/atag-and-gardn-sign-agreement-to-promote-environmental-research-in-aviation
 Imperial College London, “Green Aviation 2011: A Symposium,” organized by the Green Aviation Forum of Imperial College London, 2011. https://workspace.imperial.ac.uk/greenaviation/Public/Green%20Aviation%202011.pdf
 IATA, “Aviation and Climate Change Pathway to Carbon-Neutral Growth in 2020,” 2009. http://www.iata.org/SiteCollectionDocuments/AviationClimateChange_PathwayTo2020_email.pdf
 Design Science and Technology Sub-Group, “Greener by Design, Mitigating the Environmental Impact of Aviation: Opportunities and Priorities,” Report of the Greener by Design Science and Technology Sub-Group, 2005.
 D. McCollum, G. Gould and D. Greene, “Greenhouse Gas Emissions from Aviation and Marine Transportation: Mitigation Potential and Policies,” Prepared for the Pew Center on Global Climate Change, 2009.
 A. Jane, J. A. Leggett, Elias, Bart and D. T. Shedd, “Avia- tion and the European Union’s Emission Trading Sche- me”, CRS Report for Congress, Congressional Research Service, 2012 www.crs.gov
 N. Moharamnejad and S. Azarkamand, “Implementation of Green Productivity Management in Airline Industry,” International Journal of Environmental Science and Technology, Vol. 4, No. 1, 2007, pp. 151-158.
 “The Potential for Renewable Energy Sources in Aviation,” http://www.iccept.ic.ac.uk/pdfs/PRESAV%20final%20report%2003Sep03.pdf
 K. Lumpur, “Carbon-Neutral Growth by 2020,” 2009. http://www.iata.org/pressroom/pr/Pages/2009-06-08-03.aspx
 NRC, “NRC Meeting of Experts on NASA’s Plans for System-Level Research in Environmental Mitigation,” National Harbor, MD, 2009. http://www.aeronautics.nasa.gov/calendar/20090514.htm
 Green Aviation & Logistics Group. http://www.cssgroupsite.com/lighthouse/green-aviation-logtics-group-realises-its-vision-towards-protecting-the-environment/
 Sustainable (Green) Aviation, 2012. http://web2.aiaa.org/CourseDetail.aspx?id=4601
 Air Transport Action Group (ATAG, 2010), “Beginner’s Guide to Aviation Efficiency,” www.enviro.aero