Sampaio, Ivan Barbosa Machado, and Johanna Döbereiner. 2014. “Effects of Shading and Lime Treatments on Nitrogen Fixation Rates and on the Efficiency of Soybean Nodules (Glycine Max)”. Pesquisa Agropecuaria Brasileira 3 (1): 255-62. https://doi.org/10.1590/S1678-3921.pab1968.v3.17949.