Vasconcellos, Carlos Alberto, et al. “Soil Management and Soil Microbial Activity in Dark Red Latosol from Sete Lagoas Region, MG, Brazil”. Pesquisa Agropecuaria Brasileira, vol. 33, no. 11, Nov. 1998, pp. 1897-05, doi:10.1590/S1678-3921.pab1998.v33.5007.