Sampaio, Ivan Barbosa Machado, and Johanna Döbereiner. “Effects of Shading and Lime Treatments on Nitrogen Fixation Rates and on the Efficiency of Soybean Nodules (Glycine Max)”. Pesquisa Agropecuaria Brasileira, vol. 3, no. 1, Apr. 2014, pp. 255-62, https://doi.org/10.1590/S1678-3921.pab1968.v3.17949.