Sarmento, Eliana Casco, et al. “Prediction of Soil Orders With High Spatial Resolution: Response of Different Classifiers to Sampling Density”. Pesquisa Agropecuaria Brasileira, vol. 47, no. 9, Nov. 2012, pp. 1395-03, doi:10.1590/S1678-3921.pab2012.v47.11133.