Esteban, E., J. Tapia, Y. Martínez, and J. Albiac. “Pigouvian Taxation to Induce Technological Change and Abate Nonpoint Pollution in the Ebro Basin, Spain”. Spanish Journal of Agricultural Research, Vol. 9, no. 4, Nov. 2011, pp. 957-70, doi:10.5424/sjar/20110904-498-10.