Gallego-Ayala, J., and J.A. Gómez-Limón. “Analysis of Policy Instruments for Control of Nitrate Pollution in Irrigated Agriculture in Castilla Y León, Spain”. Spanish Journal of Agricultural Research 7, no. 1 (March 1, 2009): 24-40. Accessed August 2, 2026. https://sjar.revistas.csic.es/index.php/sjar/article/view/395.