Alves, Marcelo Eduardo, and Arquimedes Lavorent. “Remaining Phosphorus and Sodium Fluoride PH in Soils With Different Clay Contents and Clay Mineralogies”. Pesquisa Agropecuaria Brasileira, vol. 39, no. 3, Mar. 2004, pp. 241-6, doi:10.1590/S1678-3921.pab2004.v39.6763.