Ruschel, Alaides Puppin, and Herbert W. Reuszer. “Development of Nodulation and Symbiotic Nitrogen Fixation of Soybean ( Glycine Max (L.) Merril) Varieties at Different Phases of Plant Development”. Pesquisa Agropecuaria Brasileira, vol. 8, no. 8, Apr. 2014, pp. 251-6, https://doi.org/10.1590/S1678-3921.pab1973.v8.17554.