Souza, C.A. de et al. 2010. Sewage sludge effects on soil biological parameters and on soybean nodulation and yield. Pesquisa Agropecuaria Brasileira. 44, 10 (Dec. 2010), 1319–1327. DOI:https://doi.org/10.1590/S1678-3921.pab2009.v44.2290.