Andrade, S. A. L. de and Silveira, A. P. D. da (2004) “Soil microbial biomass and activity under the influence of lead addition and mycorrhizal soybean rhizosphere”, Pesquisa Agropecuaria Brasileira, 39(12), pp. 1191–1198. doi: 10.1590/S1678-3921.pab2004.v39.6895.