L. Riesgo, F. J. Areal, and E. Rodríguez-Cerezo, “How can specific market demand for non-GM maize affect the profitability of Bt and conventional maize? A case study for the middle Ebro Valley, Spain”, Span. j. agric. res., vol. 10, no. 4, pp. 867-876, Dec. 2012.