Jiménez-Jiménez, F., G. L. Blanco-Roldán, F. Márquez-García, S. Castro-García, and J. Agüera-Vega. “Estimation of Soil Coverage of Chopped Pruning Residues in Olive Orchards by Image Analysis”. Spanish Journal of Agricultural Research, Vol. 11, no. 3, July 2013, pp. 626-34, doi:10.5424/sjar/2013113-3742.