1. Sources of Greenhouse Gas Emissions, www3.epa.gov/climatechange/ghgemissions/sources/transportation
2. Crude Oil Price History Chart, www.macrotrends.net/1369/crude-oil-price-history-chart
3. K.
Wong
, OUTLOOK '16: The year the world drowned in oil, 2015
4. E.
Crooks
, Biofuel needs $70 oil to compete, says DuPont, 2015
5. H.
Chum
, A.Faaij,J.Moreira, G.Berndes, P.Dhamija, H.Dong, B.Gabrielle, A.Goss Eng, W.Lucht, M.Mapako, O.Masera Cerutti, T.McIntyre, T.Minowa and K.Pingoud, Special Report on Renewable Energy Sources and Climate Change Mitigation, 2011, p. 284