Suzuki, Luis Eduardo Akiyoshi Sanches, et al. “Relative Compaction, Physical Properties and Crop Yield in Oxisol and Alfisol”. Pesquisa Agropecuaria Brasileira, vol. 42, no. 8, Aug. 2007, pp. 1159-67, doi:10.1590/S1678-3921.pab2007.v42.7679.