A. P. Ruschel, A. R. Suhet, R. Vianni, and D. L. de Almeida, “Effect of nitrogen sources added to the soil and effect of <i> Rhizobium japonicum</i> inoculation on yield, protein and oil content of two soybean varieties”, PAB, vol. 10, no. 11, pp. 19–23, Apr. 2014.