Vernetti, Francisco de Jesus, and Solon Cordeiro de Araújo. “Effect of Phosphorus Fertilizer on the Germination and Nodulation of Soybeans”. Pesquisa Agropecuaria Brasileira, vol. 5, no. 1, Apr. 2014, pp. 251-4, doi:10.1590/S1678-3921.pab1970.v5.17677.