F. Jiménez-Jiménez, 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”, Span. j. agric. res., vol. 11, no. 3, pp. 626-634, Jul. 2013.