Goi, Silvia Regina, et al. “Nitrogen Fixation, Nodule Type and Occurrence of Ureides in Legume Trees”. Pesquisa Agropecuaria Brasileira, vol. 19, no. 13, Apr. 2014, pp. 185-90, doi:10.1590/S1678-3921.pab1984.v19.17523.