Sfredo, Gedi Jorge, Estefano Paludzyszyn Filho, and Edilson Ribeiro Gomes. 1994. “Soybean Response to Potassium and Phosphorus in a Paleudult Soil at Balsas, MA”. Pesquisa Agropecuaria Brasileira 29 (9):1359-64. https://doi.org/10.1590/S1678-3921.pab1994.v29.4185.