Unintended Consequences of Transportation Carbon Policies: Land-Use, Emission, and Innovation." Holland, Stephen P., Jonathan E. Hughes, Christopher R. Knittel and Nathan C. Parker. The Energy Journal Vol. 36, No. 3 (2014): 35-73.
Ethanol Production and Gasoline Prices: A Spurious Correlation." Knittel, Christopher R. and Aaron Smith. The Energy Journal Vol. 36, No. 1 (2014): 73-113.