Naves Silva, Marx Leandro, et al. “Green Manure - Corn Rotation and Phosphorus Adsorption in an Oxisol”. Pesquisa Agropecuaria Brasileira, vol. 32, no. 6, June 1997, pp. 649-54, doi:10.1590/S1678-3921.pab1997.v32.4693.